This document discusses the classification and properties of matter. It defines the four states of matter as solid, liquid, gas, and plasma. Matter is classified as either elements, compounds, or mixtures based on its chemical constitution. Elements are pure substances that cannot be broken down further, while compounds contain two or more elements chemically bonded together. Compounds have distinct properties from their constituent elements. The document provides examples of elements and compounds, and discusses their distinguishing physical and chemical properties. Redox reactions are described as reactions where both oxidation and reduction occur simultaneously.
Changes in matter are classified into physical and chemical changes.Physical Changes are those in which the identifying properties of substances remain unchanged. Chemical Changes are those in which new substances with new properties are formed.
Changes in matter are classified into physical and chemical changes.Physical Changes are those in which the identifying properties of substances remain unchanged. Chemical Changes are those in which new substances with new properties are formed.
This teaching Material is for Grade - 9. We provide teaching material at no cost. Please don't forget to recommend/reference our teaching Material after use.
This teaching Material is for Grade - 9. We provide teaching material at no cost. Please don't forget to recommend/reference our teaching Material after use.
Introduction to the Atom, Protons, Neutrons, Electron, Nucleus, Atomic Mass, ...www.sciencepowerpoint.com
This PowerPoint is one small part of the Atoms and Periodic Table of the Elements unit from www.sciencepowerpoint.com. This unit consists of a five part 2000+ slide PowerPoint roadmap, 12 page bundled homework package, modified homework, detailed answer keys, 15 pages of unit notes for students who may require assistance, follow along worksheets, and many review games. The homework and lesson notes chronologically follow the PowerPoint slideshow. The answer keys and unit notes are great for support professionals. The activities and discussion questions in the slideshow are meaningful. The PowerPoint includes built-in instructions, visuals, and review questions. Also included are critical class notes (color coded red), project ideas, video links, and review games. This unit also includes four PowerPoint review games (110+ slides each with Answers), 38+ video links, lab handouts, activity sheets, rubrics, materials list, templates, guides, and much more. Also included is a 190 slide first day of school PowerPoint presentation.
Areas of Focus: -Atoms (Atomic Force Microscopes), Rutherford's Gold Foil Experiment, Cathode Tube, Atoms, Fundamental Particles, The Nucleus, Isotopes, AMU, Size of Atoms and Particles, Quarks, Recipe of the Universe, Atomic Theory, Atomic Symbols, #'s, Valence Electrons, Octet Rule, SPONCH Atoms, Molecules, Hydrocarbons (Structure), Alcohols (Structure), Proteins (Structure), Periodic Table of the Elements, Organization of Periodic Table, Transition Metals, Electron Negativity, Non-Metals, Metals, Metalloids, Atomic Bonds, Ionic Bonds, Covalent Bonds, Metallic Bonds, Ionization, and much more.
This unit aligns with the Next Generation Science Standards and with Common Core Standards for ELA and Literacy for Science and Technical Subjects. See preview for more information
If you have any questions please feel free to contact me. Thanks again and best wishes. Sincerely, Ryan Murphy M.Ed www.sciencepowerpoint@gmail.com
Teaching Duration = 4+ Weeks
CH1000
Fundament
als of
Chemistry
Module 1 – Chapter 3
Elements and Atoms
• What is an element?
• An element is a fundamental substance that cannot be broken down by chemical
means into a simpler substance.
• Elements are the building blocks of matter.
• Elements can occur naturally or be synthesized in labs.
• The smallest unit of an element that retains its properties and chemical
behavior is called an atom.
• Atoms are made up of subatomic particles, but they do not have the properties of the
element
Elements
•Ten elements make up
almost 99 % of the mass of
the Earth’s crust, seawater
and atmosphere.
•Oxygen accounts for about
20 % of the atmosphere
and is found in nearly all
rocks, sand and soil.
Symbols
of the
Elements
•Each element has an
abbreviation called a symbol.
•The first letter of a symbol
must always be capitalized.
•If a second letter is needed, it
should be lowercase.
Introduction to
the Periodic Table
•Elements with similar
chemical properties are placed
in columns called groups.
•Four groups have special
identifying names, like Noble
Gases, in group 8A, which are
all unreactive gases.
Introduction to
the Periodic
Table
•The eight tall columns are called representative elements, or main group
elements. These are shown in red.
•The elements in the center are called the transition metals, or sometimes
the “inner transition metals.” These are shown in purple.
Introduction to the Periodic
Table
•Elements can be further classified
as metals, metalloids and
nonmetals.
•Notice the bold, black “staircase”
on the table. Everything to the left
of the staircase is a metal and
everything to the right of the
staircase is a non metal.
• The exception is Hydrogen,
which is why some periodic
tables will show hydrogen
disconnected from the main
body of the table.
•The elements in grey touching the
“staircase” are called metalloids, or
semiconductor metals. These metals
are used in the semiconductor
industry.
Metals,
Nonmetal
s and
Metalloids
• Solid at room temperature (except mercury)
• Shiny
• Good conductors of heat and electricity
• Malleable (can be shaped)
• Ductile (can be drawn into wires)
• Most metals have a high melting point and density
Metals
• Not shiny
• Have fairly low melting points and densities
• Are poor conductors of heat and electricity
Non
Metals
• Metalloids have properties between metals and
nonmetals.
• These elements are positioned diagonally on the Periodic
Table separating the metals and nonmetals.
Metalloid
s
Diatomic Elements
•Diatomic molecules
contain exactly two atoms
•Seven elements exist as
diatomic molecules and are
shown in the table to the
left
•Diatomic elements can be
separated.
Compounds
•A compound is a substance
containing two or more
elements that are chemically
combined in a definite
proportion by mass
•Compounds, unlike elements,
can be decomposed chemically
into simpler substances
...
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
3. Modern Classification
• On the basis of its physical state, matter is
classified into solid, liquid and gas.(Physical
Change)
• All these three states exist under normal
temperature and pressure conditions
• The fourth state of matter is Plasma.
• on the basis of its chemical constitution,
matter is classified into element, compound
and mixture.( Chemical change)
6/26/2015
4. Physical and Chemical Changes
• Physical Change:
• A change of matter in size, shape or
state without any change in identity is called a
physical change
• NO new substance is formed.
• These changes are easily reversible or temporary.
• An example is dissolving salt in water.
• Other examples of physical change include:
melting, boiling, mixing 2 solids or liquids.
5. • Chemical Change:
• A change of matter that occurs when atoms
link together in a new way, creating a new
substance different from the original
substance.
• A NEW substance is formed.
• These changes are irreversible or permanent.
• The new substance formed will have different
properties compared to its original elements. (E.g.
different melting and different chemical reactions
from the original substance.)
Physical and Chemical Changes
6. • One can recognize a chemical change from 2
observations:
• The new substance has a different appearance, such as
different color or different physical state.
• An example is the electrolysis of water.
• Reason: Electrolysis of water produces two new
substances, Hydrogen gas and oxygen gas. Hydrogen
and oxygen are both gases but water is a liquid.
• A lot of heat is given out in a chemical changes.
• Chemical changes are called chemical reactions.
Physical and Chemical Changes
9. Introducing Little Miss
“Element”
Hi! I am Little Miss “Element”
I am PURE SUBSTANCE
I cannot be broken down into any
simpler substance by means of a
chemical reaction* or electricity**!
*Chemical process refers to
chemical reaction or heat
**Electricity refers to electrolysis
I have
got new
friends
10. Elements
Definition of an element:
An element is a pure substance which
cannot be split up into two or more
simpler substances by chemical means.
Sugar is not an element as it can be
broken down into carbon and water.
11. Note that an element:
• Consists of only one kind of atom,
• Cannot be broken down into a simpler type of
matter by either physical or chemical means
• Can exist as either atoms (e.g. argon) or
molecules (e.g., nitrogen).
• Cannot possible to obtain a simpler substance
chemically from these elements.
• Can only make more complicated substances
from it.
Elements
12. - They are arranged in the Periodic Table, classified as metals
and non-metals.
- They may consist of atoms of same element or molecules of
the same element.
Periodic Table
14. Examples of elements
Is the smallest particle
of an element and has
the same chemical properties
of the element
Is made up of two or more
atoms that are chemically
bonded together
(note: these atoms are of the
SAME element!!)
Hi, I am from the
“Noble gas” family
and I work alone
We same
same!!
18. What is an atom?
Examples of models of atoms:
H Na Cl
Hydrogen
atom
Sodium atom Chlorine
atom
19. Molecules
Very few elements exists as
atoms besides elements such
as helium and neon.
Most elements exist as
molecules.
For example, hydrogen
is H2.
Ozone is O3.
20. Hydrogen (H2) is a
diatomic molecule.
Ozone (O3) is a
triatomic molecule.
Molecules consisting of a
few atoms are called
polyatomic molecules.
23. Chemical Symbols of Elements
Chemists use symbols to represent elements.
For example, O represents oxygen while Fe
represents iron.
Element Symbol Element Symbol
Calcium Ca Mercury Hg
Carbon C Neon Ne
Hydrogen H Silicon Si
Iron Fe Sodium Na
24. Classification of Elements – Metals
and Non-metals
The elements can be classified according to their
various properties.
There are two major groups of elements –
metals and non-metals.
Iron is a metal. Oxygen is a non-metal.
There are some elements called metalloids
which behave like both metals and non-metals.
Metals and non-metals are grouped separately
on the Periodic Table.
25. Physical Properties metals and non-metals
Property Metals Non-metals
Physical state at room
temperature
Usually solid (occasionally
liquid)
Solid, liquid or gas
Malleability Good Poor – usually soft or
brittle
Ductility Good
Appearance (Solids) Shiny (lustrous) Dull
Melting point Usually high Usually low
Boiling point Usually high Usually low
Density Usually high Usually low
Conductivity (thermal and
electrical)
Good Very poor
26. ELEMENTS & SYMBOLS
S.No NAME SYMBOL PHYSICA
L STATE
NAME SYMBOL PHYSICAL
STATE
1
2
3
4
5
6
7
8
9
10
Aluminium
Calcium
Copper
Iron
Magnesium
Mercury
Potassium
Sodium
Zinc
Gold
Al
Ca
Cu
Fe
Mg
Hg
K
Na
Zn
Au
Solid
Solid
Solid
Solid
Solid
Liquid
Solid
Solid
Solid
Solid
Argon
Bromine
Carbon
Chlorine
Silicon
Sulphur
Hydrogen
Iodine
Nitrogen
oxygen
Ar
Br
C
Cl
Si
S
H
I
N
O
Gas
Liquid
Solid
Gas
Solid
Solid
Gas
Solid
Gas
Gas
* Physical states are given at room temperature.
METALS NON- METALS
6/26/2015
27. Introducing Little Miss “Naughty”
Harlow! Hehee!!!
*giggles*
I am also a PURE SUBSTANCE
I am made up of a fixed number of
two or more elements chemically
combined.
28. Atoms
• Everything in this world is made of billions of atoms.
• The smallest atom known as hydrogen.
• Each atom is represented as a sphere having a diameter of 7 X 10-8 mm.
• Different elements have different diameter and different masses.
• Chemists use shorthand symbols to label the elements and their atoms.
• The symbols consists of 1, 2 or 3 letters.
• For example
1. C - Carbon
2. Cl - Chlorine
• Some symbols seems to have no relations with the name of the element.
For example:
1. Na – Sodium
2. Pb - Lead
• These symbols come from their Latin names.
6/26/2015
29. Molecules
• The atoms of same elements join together to form a
molecule.
• The small group of atoms are called molecules.
• For example: when the atoms of elements hydrogen, oxygen,
nitrogen, fluorine, chlorine, bromine and iodine are each
joined in pairs and are known as diatomic molecules.
• but in phosphorus and sulfur the atoms are joined in larger
numbers, 4 and 8 respectively (P4, S8)
• The gaseous elements helium, neon, argon, krypton, xenon
and radon are composed of separate and individual atoms.
• When an element exists as separate atoms, then the
molecules are said to be monatomic.
6/26/2015
30. Compounds
Note that a compound:
• can be broken down into a simpler type of
matter (elements) by chemical means (but not
by physical means),
• has properties that are different from its
component elements, and
• always contains the same ratio of its
component atoms.
31. A compound is a substance which is made up of two or more
elements chemically combined together.
What is a compound?
- Chemical reactions taking place.
Cu
Qn: Is this a compound?
It only contains one type of
element.
Qn: Is this a compound?
H HIt only contains one type of
element.
H
O
H
O
O
Qn: Is this a compound?
It is not chemically
combined.
32. So, what is a compound then?
O
HH
Water
N
H
HH
Ammonia gas
Consists of two or more elements
And
They are chemically combined together!
33. Compounds
Microscopic view of the
molecules of the
compound water (gas
phase). Oxygen atoms
are red and hydrogen
atoms are white.
Hydrogen + Oxygen Water
H2 + O2 2H2O
35. Making compounds fromtheir elements
Example: Making Magnesium Oxide compound
Magnesium + Oxygen Magnesium oxide
elements
compound
+
Silvery-White colourless gas
heat
heat
White
Magnesium + Oxygen → Magnesium oxide
2Mg + O2 → 2MgO
36. Oxidation
• When the substances are combined with
oxygen they are said to have been oxidised.
This process is Known as oxidation.
• Eg: Hydrogen and Magnesium combine with
Oxygen
37. Reduction
• It is the opposite of oxidation.
• In this process oxygen is removed instead of
being added.
39. GCSE
Oxidation:
•Gain of oxygen
•Loss of electrons
Reduction:
•Loss of oxygen
•Gain of electrons
Increase in
oxidation
number
Decrease in
oxidation
number
40. Redox reaction
Example
• Removing Oxygen in the extraction of iron from
iron(III)oxide
• This can be done in a blast furnace with carbon monoxide.
• The iron(III)oxide loses oxygen to the carbon monoxide and
is reduced to iron.
• Carbon Monoxide is the reducing agent.
• Carbon monoxide is oxidised to carbon dioxide by the
iron(III)oxide.
• The iron(III)oxide is the oxidising agent.
• iron(III)oxide + carbon iron + Carbon dioxide
• Both reduction and oxidation have taken place in this
chemical process, and so this is known as a redox reaction.
6/26/2015
41. Reducing Agent
• A reducing agent is a substance that reduces
another substance during a redox reaction
6/26/2015
42. Oxidising Agent
• An oxidising agent is a substance which
oxidises another substance during redox
reaction.
6/26/2015
43. Little Miss “Naughty”
Property #1
I can be represented as
a “chemical formula”
The different elements
present in a compound
are combined in a fixed
ratio
General Rules:
- Only write the name of the metallic element
first
- Write the number of atoms of any element
in the compound in subscript
(applies to only 2 or more atoms)
- “ide” will always be written at the
end of the non metal element
Special Rules:
• Does not apply to organic compounds
(chapter 18 onwards)
44. Little Miss “Naughty”
Property #2
I am formed by atoms
of different elements.
However, I do not have
the properties as them.
Examples
• Na + Cl2 NaCl
(s) (g) (s)
• H2 + O2 H2O
(g) (g) (l)
45. Little Miss “Naughty”
Property #3
Because of my chemical bonds, I
cannot be broken down by physical
means. I can only be broken down
by chemical reaction or electricity.
Electrolysis
(breaking down of compound by electricity)
2MgCl(s) Mg(s) +Cl2(g)
Thermal Decomposition
(breaking down of compound by heat)
HgO(s) Hg(s) + O2(g)
46. How do we name compounds?
Rule 1
A compound made up of two elements
has a name that ends in -ide.
• Sodium chloride — made up of the elements
sodium and chlorine
• Zinc oxide — made up of the elements zinc and
oxygen
• Carbon dioxide — made up of the elements
carbon and oxygen
47. How do we name compounds?
Rule 2
A compound that contains hydroxide ions , OH–
(a negatively charged ion made up of oxygen
and hydrogen) is named a hydroxide.
• Potassium hydroxide — contains potassium ions
and hydroxide ions
48. How do we name compounds?
Rule 3
A compound that contains a negatively
charged polyatomic ion containing oxygen
usually has a name ending in –ate.
• Copper(II) sulphate — contains oxygen atoms in
the sulphate ion
• Sodium nitrate — contains oxygen atoms in the
nitrate ion
49. Fixed Composition of Compounds
For example, water (H2O) is a compound made
only by joining together two atoms of hydrogen
to one atom of oxygen.
That is, the ratio of hydrogen atoms to oxygen
atoms in water is always 2 : 1.
A compound is made up of different elements
chemically combined in a fixed ratio.
51. How do we write chemical formula?
Rule 1
For many compounds that contain both
metallic and non-metallic elements, the
symbol of the metallic element is written
first.
• calcium oxide (CaO)
• sodium chloride (NaCl)
• magnesium carbonate (MgCO3)
52. How do we write chemical formula?
Rule 2
The number of atoms is written as a
subscript, to the right of the atom’s symbol.
• water (H2O, not H2O or 2HO)
• magnesium carbonate
(MgCO3, not MgCO3 or MgC3O)
53. How do we write chemical formula?
Rule 3
It is not necessary to write the
subscript ‘1’.
• water (H2O, not H2O1)
• calcium oxide (CaO, not Ca1O1)
54. How do we write chemical formula?
Rule 4
The oxygen atom is usually written at
the end of the formula.
• water (H2O, not OH2)
• carbon dioxide (CO2, not O2C)
• nitric acid (HNO3, not O3NH)
55. How do we calculate the number of
atoms in a formula?
Pb(NO3)2
Number of nitrogen (N) atoms
= 1 x 2 = 2Number of lead (Pb) atoms = 1
Number of oxygen (O) atoms
= 3 x 2 = 6
56. Heat can be used to break down compounds
into elements or simpler compounds. Such a
chemical reaction is called thermal
decomposition.
Compounds can be Decomposed
Mercury(II) oxide
Oxygen
57. Summarizing
• A compound is made up of two or more
elements chemically joined together
• A compound has a fixed composition
• Every compound has a unique chemical
formula
• A compound has a completely different
properties from its elements
• A chemical reaction (decomposition or
electrolysis) is needed to separate the
elements in the compound
60. Balancing chemical equations
• Word equations are used to represent
chemical reactions.
• But better and more useful method is to
produce a balanced chemical equation.
• This type of equation gives the formulae of
the reactants and the products.
• And also it shows the relative numbers of each
particle involved.
6/26/2015
61. Law of Conservation of Mass
You need to remember this law!
• The Law of Conservation of Mass states: that
mass is neither created nor destroyed in any
chemical reaction. Therefore balancing of
equations requires the same number of atoms
on both sides of a chemical reaction.
• The number of atoms in the Reactants must
equal the Number of atoms in the Products
62. Law of Conservation of Mass
• The mass of all the reactants (the substances
going into a reaction) must equal the mass of
the products (the substances produced by the
reaction).
• Reactant + Reactant = Product
63. Steps to Balancing a Chemical Equation
1. Write all reactants
on the left and all
products on the
right side of the
equation arrow.
Make sure you write
the correct formula
for each element
2. Use coefficients in front
of each formula to
balance the number of
atoms on each side.
64. Steps to Balancing a Chemical Equation
3. Multiply the coefficient
of each element by the
subscript of the
element to count the
atoms. Then list the
number of atoms of
each element on each
side.
4. It is often easiest to start
balancing with an element
that appears only once on
each side of the arrow.
These elements must have
the same coefficient. Next
balance elements that
appear only once on each
side but have different
numbers of atoms. Finally
balance elements that are in
two formulas in the same
side.
65. A simple equation, such as the synthesis of
Iron (II) sulfide
• iron + sulfur Iron (II) sulfide
• Replace the words with symbols for the reactants
and products.
• Fe + S FeS
• Note that in a chemical equation, by convention,
we use the arrow “ " instead of the equals “ =
".
• There is same number of each type of atom on
both sides of the equation. So this is the balanced
chemical equation.
66. • The last stage is to put in state of matter
symbols, (s, l, g, aq), as appropriate (solid,
liquid, gas, aqueous or dissolved in water)
• Fe(s) + S(s) heat FeS(s)
A simple equation, such as the synthesis of
Iron (II) sulfide
67. Re-cap of steps from rule 4:
• Balance elements that appear only once on
each side of the arrow.
• Next balance elements that appear only once
on each side but have different numbers of
atoms.
• Finally balance elements that are in two
formulas in the same side.
68. First you need an equation with the correct “formulae”
………. You’ll probably be given this in the question
Just like this one
Mg + O2 MgO
Then all you do is list the atoms that are involved
on each side of the arrow
Mg + O2 MgO
Mg
O
Mg
O
69. [1] Just count up the atoms on each side
Then start balancing:
Mg + O2 MgO
Mg
O
1
1
1
2
[2] The numbers aren’t balanced so then add “BIG”
numbers to make up for any shortages
And adjust totals
Mg + O2 MgO
Mg
O
1
1
1
2
2
2
2
70. Mg + O2 MgO
Mg
O
1
2
2
2
2
But the numbers still aren’t equal, so add
another “BIG” number
2
And adjust totals again
NOW BOTH SIDES HAVE EQUAL
NUMBERS OF ATOMS
WE SAY THAT THE
EQUATION IS BALANCED!!
2
71. Try to balance these equations using the same
method:
[1] Na + Cl2 NaCl
[2] CH4 + O2 CO2 + H2O
[4] Al + O2 Al2O3
[3] Li + HNO3 LiNO3 + H2
72. How did you get on??
[1] 2 Na + Cl2 2 NaCl
[2] CH4 + 2 O2 CO2 + 2 H2O
[4] 4 Al + 3 O2 2 Al2O3
[3] 2 Li + 2 HNO3 2 LiNO3 + H2
Here are the answers:
73. Instrumental techniques
Modern chemists use a range of instruments to analyse and identify substances. Most
produce quantitative data, which requires expert interpretation.
There are many different types of machine used for analysis, each producing a different
type of information, such as:
whether a substance is pure or a mixture
the molecular mass of a compound
the types of bonds in a molecule
the arrangement of atoms in a molecule
the isotopes of different atoms in a substance.
74. Instrumental techniques
• Many instrumental methods are developed.
• Some methods are suited for identifying
elements.
6/26/2015
75. Atomic absorption spectroscopy
Atomic absorption spectroscopy (ABS) is a technique that allows elements to be
identified, and their concentration measured down to just a few parts per billion.
ABS has many uses:
environmental chemistry – to analyse pollutant
concentrations in air and water
medicine – to analyse concentrations of toxic chemicals in
blood and urine
building – to check for impurities in concrete and steel
mining – to check how much
metal is in an ore.
76. • Some methods are suited to the identification
of compounds
6/26/2015
77. Infrared Spectroscopy
• This is used to identify the compounds by
showing the presence of particular groupings of
atoms.
• This is used in Pharmaceutical industries to
identify and discriminate between drugs that are
similar in structure.
• Eg: Penicillin type drugs.
• Used to identify both organic and inorganic
molecules.
• Samples can be solid, liquid or gas.
6/26/2015
78. Infrared Spectroscopy
• This is used to monitor environmental
pollution.
• It has biological uses in monitoring tissue
physiology including
• Oxygenation,
• Respiratory status
• Blood flow damage
6/26/2015
79. Instrumental Techniques
• Forensic scientists used this methods because
• They are very accurate
• They require tiny amounts of sample
6/26/2015
• Other techniques utilised are nuclear magnetic
resonance spectroscopy and Ultraviolet/
Visible Spectroscopy
81. Introducing Little Mr. “Mixture”
Burp!!!! I am messy!
I am formed when two or more substances joined
together physically (without chemical bonds)
I have the same properties as all the substances
AIR
I am his best friend!
82. Mixtures
Definition of a mixture:
A mixture is not a pure substance as it
contains a mixture of atoms of
molecules which are not chemically
combined together.
84. Microscopic view of a
gaseous mixture
containing two
elements (argon and
nitrogen) and a
compound (water).
Mixtures
85. Mixtures
• Examples of mixtures include muddy water
and air.
Air is made up of gases such as nitrogen and
oxygen mixed together.
86. Little Mr “Mixture”
I do not have a fixed composition of the
substances.
A Mixture can be:
• element + element
• element + compound
• compound + compound
(Refer to page 59, Fig 4.7)
He is a “boo-boo!”
He can be separated to its
substances by physical methods
87. A mixture of 2 elements
A mixture of two
elements, e.g. neon (Ne)
and hydrogen (H2)
88. A mixture of 1 element and
1 compound
A mixture of one element
and one compound, e.g.
hydrogen (H2) and
ammonia (NH3)
89. A mixture of 2 compounds
A mixture of two
compounds, e.g. water
vapour (H2O) and
carbon dioxide (CO2)
90. CHARACTERISTICS OF MIXTURE
• It is an impure substance
• No formula
• They can be mixed in any ratio.
• The properties of the mixture are the properties of
its constituents.
• Constituents can be easily seperated by physical
methods e.g. heating, drying, crystallization,
distillation etc.
• It is either homogenous or heterogenous.
90،جمعه10،رمضان1436
91. Mixtures
Homogenous mixture
Is the type of mixture that has a completely
uniform composition throughout itself.
It’s components are evenly distributed
throughout the sample.
92.
93. Homogenous or Heterogenous?
1. Air
2. Salt water
3. Tea
4. Brass
5. Vinegar
6. Hydrogen peroxide
7. Steel
1. Salad dressing
2. Apple
3. Sand
4. Paint
5. Granite
6. Laundry detergent
7. Cereal
94. Solutions
• Is the special name that scientists give to
homogenous mixtures.
• Solutions may be gases, liquids or solids.
• An example: solution of sugar in water.
95. Solutions
Some common types of solutions
System Examples
Gas-gas CO2 and O in N (air)
Liquid-gas Water vapor in air
Gas-liquid CO2 in H2O (Soda water)
Liquid-liquid Acetic acid in H2O (vinegar)
Solid-liquid NaCl in H2O (brine)
Solid-solid Cu in Ag (Sterling silver)
96. Phases
• Any part of a system with uniform
composition and properties is called a phase.
• On a homogenous mixture you have “one
phase” only.
• On a heterogenous mixture you have “two or
more phases”.
99. Difference between Mixtures and Compounds
Example
• A mixture of iron fillings and sulphur looks
different from the individual elements.
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• This mixture has the
properties of both
iron and sulfur.
• A magnet can be used to
separate the iron
fillings from the sulfur
100. Difference between Mixtures and Compounds
Example
• This mixture has the properties of both iron
and sulfur.
• A magnet can be used to separate the iron
fillings from the sulfur.
• Substances in a mixture have not undergone a
chemical reaction.
• It is possible to separate them by using their
physical properties.
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101. • If the mixture of iron and sulfur is heated a
chemical reaction occurs and a new substance
is formed called iron (II) sulfide.
• Iron + Sulfur iron (II) sulfide.
• iron (II) sulfide has different properties to the
mixture of iron and sulfur.
• This iron (II) sulfide would not be attracted
towards a magnet.
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Difference between Mixtures and Compounds
Example
heatt
102. Different properties of iron, sulfur, an iron/sulfur
mixture and iron (II) sulfide
Substance Appearance Effect of a magnet Effect of dilute HCl
Iron Dark grey
powder
Attracted to it Very little action
when cold. When
warm, a gas is
produced with a lot of
bubbling
Sulfur Yellow powder None No effect when hot or
cold
Iron/Sulfur mixture Dirty yellow
powder
Iron powder
attracted to it
Iron powder reacts as
above
iron (II) sulfide Black solid No effect A foul-smelling gas is
produced
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103. Differences between mixtures and
compounds
*giggles*
HeE
stupid…
Laugh what? I
know I am a little
“bushy and hairy”
than you…
Little Miss CompoundMr Messy
108. EXTRA!
• Human body is made up of 28 elements?
• About 99% our mass is made up of the 6
main elements
– Oxygen (65%)
– Carbon (18%)
– Hydrogen (10%)
– Nitrogen(3%)
– Calcium (1.5%)
– Phosphorus (1.5%)
109. Seperating Solid Mixtures
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Suppose you had a mixture of iron nails, salt
and water…
How would you separate this mixture
completely?
Based on which physical properties would you
base your method on?
110. Distillation
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How would you separate the components in
tap water?
Distillation
A liquid is boiled to produce vapor that is
then condensed again to a liquid
112. Seperating Solid/Liquid mixtures
• Sedimentation and Decantation
• Sedimentation is the process of separating an
insoluble solid from a liquid in which it is
suspended by allowing it to settle to the
bottom of the container. If this also involves
pouring off of the liquid leaving the solid
behind, it is called decantation.
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113. Crystallisation
Crystallisation is a sophisticated form of evaporation technique
in which crystals of the solute are encouraged to develop during
the process of “dissolving out” from the solution as the solvent
evaporates.
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114. Evaporation
Evaporation is used for recovering dissolved solid
substances from solutions by evaporating the solvent.
The solute “dissolves out” and is left behind.
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115. 6/26/2015
Differential Centrifugation
The simplest form of separation by centrifugation is differential
centrifugation, sometimes called differential pelleting (see Figure
1). Particles of different densities or sizes in a suspension will
sediment at different rates, with the larger and denser particles
sedimenting faster. These sedimentation rates can be increased by
using centrifugal force. A suspension of cells subjected to a series
of increasing centrifugal force cycles will yield a series of pellets
containing cells of decreasing sedimentation rate.
116. Seperating Liquid Mixtures
Liquids are divided into two:
Miscible Liquids
Immiscible Liquids
Definition of Miscible liquids:
Miscible Liquids are formed when when two
substances mix together completely.
For example: Apple juice and Pineapple Juice.
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118. 6/26/2015
Fractional Distillation
Fractional distillation is the process of separating two or more miscible liquids by a
modified distillation process, in which the distillates are collected as fractions having
different boiling points. The separation of the liquids by this method is based on the
difference in their boiling points. (Fig. 5)
Fractional distillation makes use of a fractionating column or distillation
column, a tube which provides different temperature zones inside it during distillation,
the temperature decreasing from bottom to top. It provides surfaces on which
condensations (of less volatile liquids) and vaporizations (of more volatile liquids)
can occur before the vapours enter the condenser in order to concentrate the more
volatile liquid in the first fractions and the less volatile components in the later fractions.
Fractional distillation is very effective is separating mixtures of volatile components, and
is widely used in laboratories and industries.
121. Chromatography
When we separate two or more solids that are
soluble. This type of problem is encountered
when you have mixtures of coloured materials
such as inks and dyes.A technique called
chromotography is widely used to separate these
materials so that they can be identified.
There are several types of chromatography,
however they all follow the same basic principles
the simplest kind is paper chromotography. To
separate the different coloured dyes in a sample
of black ink, a spot of the ink is put on to a piece
of chromatography paper. This paper is then set
in a suitable solvent.6/26/2015
122. Chromotography
As the solvent moves up the paper the dyes are
carried with it and begin to separate. They
separate because the substance have different
solubilities in the solvent and are absorbed to
different degrees by the chromotography
paper as they result they are seperated
gradually as the solvent moves up the paper.
The chromotogram shows how the ink
contains three dyes.
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123. Solvent Extraction
Sugarcan be obtained from crushed sugar cane
by adding water. The water dissolves the sugar
from the sugarcane. This is an example of
solvent extraction. In a similar way some of
the green substances can be removed from
ground - up grass using ethanol. The
substances are extracted from the mixtures by
using a solvent which dissolves only those
substances required.
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124. Criteria for purity
Drugs are manufactured to very high degree of
purity. To ensure that the highest possible purity
is obtained the drugs are dissolved in a suitable
solvent and subjected to fractional crystallisation.
It is illegal to put anything harmful into a food. Also
government legislation requires that a lot of
testing takes place before a new pharmaceutical
is marketed.
Throughout the chemical, pharmaceutical and food
industries it is essential that the substance used
are pure. The purity of a substance can be gauged
by:6/26/2015
125. Criteria for purity
• Its melting point – if it is a pure solid it will have a
sharp melting point. If an impurity is present then
the melting point takes over a range of temperature
• Its boiling point – if it is a pure liquid the
temperature will remain steady at its boiling point.
If the substance is pure then the mixture will boil
over a temperature range.
• Chromotography – if it is a pure substance it will
produce only one well defined spot on a
chromatogram. If impurities are present then
several spots will be seen the chromotogram.
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126. Conclusion
An element is a pure substance which cannot be split up
into two or more simpler substances by chemical
means.
A compound consist of a fixed number of different kinds
of atoms chemically combined together.
A mixture is not a pure substance as it contains a
mixture of atoms of molecules which are not
chemically combined together.