This document provides an introduction to chemistry, including definitions of key terms like elements, compounds, mixtures, physical and chemical properties, and states of matter. It explains that chemistry studies the structure and properties of matter, and the changes matter undergoes. It also introduces the periodic table, describing how elements are organized by their atomic number and valence electrons.
3. Chemistry
● Chemistry studies the structure and properties of matter
and the changes it undergoes.
● Chemistry focuses on chemical rather than physical
change.
13. Gases
● Do not have constant
volume
● Compressible
● Do not have a definite
shape
● Move freely
● Fill the space of a container
482 m/s km/hr??
14. (Gas = Vapor)
25o
C 120o
C
A substance is
a gas if it is
gaseous at
room
temperature
(25o
C).
15.
16.
17.
18. Classifying Matter
Substances
● Pure
● Element
● A substance is an
element if you can
find it on the
periodic table
● Compound
● A substance is a
compound if it has a
chemical formula
● Mixtures (Impure
Substances)
● Homogeneous
Mixture
● A homogeneous
mixture is uniform,
also called a solution
● Heterogeneous
Mixture
● A heterogeneous
mixture is not
uniform
19. Substances
● Pure Substances
● Elements
● K Na Ne Ag
● Compounds
● O2
NaCl H2
0 Fe2
O3
● Mixtures
● Homogeneous Mixture
● Water with salt
● Tylenol
● Apple Juice
● Heterogeneous Mixture
● Pozole
● Lago de Chapala
● Pizza
20. Physical Properties of Matter
● Physical Property
● a characteristic that can be
observed or measured
without changing the objects
composition.
● Density
● color
● odor
● hardness
● melting point and
boiling point
● Extensive (Exterior)
● Depend on the amount
present
● Intensive (Interior)
● Do not depend on the
amount present
21. Extensive
How much does the copper wire/plastic weigh?
Intensive
Does the copper wire/plastic conduct electricity?
22. Chemical Properties of Matter
Chemical Property
● Ability to:
● Combine with another
substance
● Change into another
substance
● Examples
● Flammability
● Gasoline vs Water
● Toxicity
● Chlorine vs Water
● Ability to oxidize
● Iron vs Aluminum
23.
24.
25. Change
● Physical Change
● a usually reversible change,
chemical properties do not
change
● H20 H20 H2O
● Chemical Change
● A reaction involving the rearrangement
of the atoms of one or more substances
● There is a formation of at least one new
substance
26.
27. Changes in Matter
● Physical Change
● Phase Change -
Requires changes in
pressure and/or
temperature
● A transition from
one state of
matter to another
● boil, freeze,
condense,
vaporize, or melt
Physical Changes
depend on Physical
Properties or
Chemical
Properties?
At what temperature does copper change
state from a solid to a liquid?
What type of property determines this
change?
33. Vocabulary
● Atom
● Proton
● Neutron
● Electron
● Isotope
● Atomic Number
● Atomic Mass
● Period
● Group
● Family
● Valence Electrons
● Electron-dot Structure
39. Periodic Table
● Organized according
to:
● Atomic Number
● The number of
protons in an atom
● Electron Structure
● Divided into:
● Periods
● Groups
48. Reactivity
The attraction that a bonding pair of electrons feels for a particular nucleus.
Depends on:
● the number of protons in the nucleus;
● the distance from the nucleus;
● the amount of screening by inner electrons.
51. All elements want to have a complete set of valence electrons; elements will react until they have a
complete set. A complete set consists of eight electrons, this explains why Noble gases do not react. Helium is
a Noble gas, even though its outer orbital only has two electrons. Helium’s outer orbital only accepts two
electrons, therefore its set of valence electrons is complete; it will not react.