Elements and compounds

1. GRADE 7 SCIENCE

2. OBJECTIVES
 After going through this module, you are
expected to:
1. describe an element and a compound;
2. explain the difference between an
element and a compound; and
3. cite examples of elements and
compounds (S7MT-Ig-h-5).

3. • Review Matter
• Phases of Matter
• Classification of Matter
• Elements
• Compounds

5. VIDEO

6. • Elements could either have
physical and chemical
properties.
• Physical Properties
• This is a property that can
be readily observed
through the human senses.
• Chemical Properties
• This is a property that can
be attained once an
element undergoes change
in composition such as
burning.

7. 1. Luster- shiny in
appearance
2. Volume- amount of
space occupied by an
object.
3. Color- the aspect of the
appearance of object and
light sources.
4. Mass- the amount of
material it contains.
5. Shape- appearance or
form of a sample matter.

8. 1. Flammability- ability to be
burnt easily or undergo
combustion.
2. Oxidation- to be rusted or
being oxidized and form
oxides.
3. Toxicity- the relative degree
of being poisonous.
4. Acidity- the state of being
acidic by nature.
5. Stability- resistance to
chemical change or to
physical disintegration

9. • An element is a pure
substance that cannot
be broken down into
simpler substances but
can be chemically
combined with one
another to produce
another substance.
• This makes elements
as a homogenous
example of matter.

10. 1. Pure substance
 Made of only 1 type
of particle
 Ex: copper wire only
has copper atoms
2. Can’t be separated
into simpler
substances by
chemical or physical
means

11. An element is a substance that is made from one kind of atom only. It
cannot be broken down into simpler substances.
An element
An element
atom atom

12. Now look in your periodic table and find the symbols
of the following elements, then find out if it is a
metal or a non-metal:
Copper ……..
Iron ………..
Magnesium ………..
Chlorine ………..
Carbon …………
Sodium …….
Lead ……….
Gold ………
Calcium ……..
Fluorine ……….

13. Now look in your periodic table and find name that
corresponds to the following symbol:
Fe ……..
Mg ………..
Ag ………..
K ………..
C …………
Ca …….
Na ……….
N ………
Ne ……..
Pb ……….

14. Compounds are made up
of two or more elements
that are chemically
combined producing a
new set of properties.

15.  Do you know any compounds?
 How are they different from elements?
 Characteristics
1. Found in nature more often than pure elements
2. Have more than one element
3. Elements are chemically bonded to each other
– Mg + O2 makes MgO
4. Pure substances that occur in fixed ratios by mass
– 1g H to 8g of O in every water molecule
5. Can’t be separated by physical means
6. Have their own unique set of properties

16. A compound is a substance that is made
from more than one element.
atom atom
A compound made up of
2 different elements
A compound made up of
7 different elements

17. A compound can be broken down into
elements
A compound made up of 3
different elements
An element
An element
An element

18. Properties of Compounds
1. Compounds cannot be
separated into other substances
by physical methods but by
chemical means only.

19. Properties of Compounds
2. Shorthand in writing compounds is
chemical formulas while elements are
chemical symbols.
Example:
water - H2O (chemical formula)
hydrogen - H (chemical symbol)
oxygen - O (chemical symbol)

20. Properties of Compounds
3. Elements in compounds are always combined in fixed
proportions.
Name of the
Compound
Chemical
Formula
Composition Proportion
A. water H2O 2 Hydrogen (H)
1 Oxygen (O)
2:1
B. table salt NaCl 1 Sodium (Na)
1 Chlorine (Cl)
1:1
C. table sugar C12H22O11 12 Carbon (C)
22 Hydrogen (H)
11 oxygen (O)
12:22:11

21. ADDITIONAL INPUTS
1. Generally, compounds have chemical names and
common names
Chemical formula Chemical name Common name
A. NaCl sodium chloride table salt
B. H2O dihydrogen oxide water
C. CH4 carbon tetrahydride methane

22. ADDITIONAL INPUTS
2. Compounds are useful in our daily needs.
Name of the
Compound
Chemical
formula
Uses
A. water H2O
drinking, washing,
watering, cleaning
B. table salt NaCl seasoning
C. table sugar C12H22O11 sweetener
D. agua
oxigenada
H2O2 cleaning wounds

23. 1. Read the poem “The Lost Element”, and
let the students identify the elements (Oral or
written).
2. ‘My Idol Transformer’, let the students
determine the metallic and nonmetallic
elements in this activity.

24. THE LOST ELEMENT
by: Jaypee Kadalem Balera
I think I was lost
My home is too far at any cost
I am tired finding home-made of lead
So that solar radiation will not anymore be
spread,
The heat from Sun makes me float
Like Helium inside a balloon
that makes it bloat As I go far,
I feel numb and bursting
Like a bullet powder made of Potassium
Nitrate that makes us shaking

25. I hope I can go home now
I feel my lungs did not function somehow
Hope oxygen will fill me completely Before
carbon dioxide will be mine totally
As I walk in the lonely road above the
mountains
As I walk in the lonely road above the
mountains
It is sad to see land mine of gold and copper be
broken This shows how the environment
suffered much everyday
Hope my home will be back with me again like a
brand-new day
My body is already in pained and drained
With essential elements from water made up of
hydrogen and oxygen I want to quench my thirst
soon
To fast track the lost element which is my
Home.

26. Material Made up of: Element or
compound
Water Hydrogen and Oxygen
Coal Carbon
Carbon dioxide Carbon and Oxygen
Oxygen Oxygen
Chalk Calcium, Carbon &
Oxygen
Wax Carbon & Hydrogen
Table salt Sodium & Chlorine
Caffeine Carbon, Hydrogen,
Nitrogen & Oxygen

27. Material Element or compound
Water Compound
Coal Element
Carbon dioxide Compound
Oxygen Element
Chalk Compound
Wax Compound
Table salt Compound
Caffeine Compound