This is a topic about Grade 7 Science which discusses the difference between elements and compounds

1. elements
and
compound
ELEMENTS

2. LEARNINGOBJECTIVES
1. Identify materialswhichcontain elements.
2. Describeelements based on physical and
chemicalproperties.

3. MATTER
Matter is anything that occupies space and has mass. Earth is
composed of different forms of matter. The air you breathe, the
water you drink, and the food you eat are examples of matter.
Chemistry is the branch of science that deals with thestudy of
matter, it’s composition, and the changes it undergoes.

4. Classificationof Matter

5. Pure Substance
A puresubstance is matter that has distinct properties and
compositions that do not vary from sample to sample. It cannot
be separated into two or moresubstances by physical or
mechanical means. Distilled water is an example of a pure
substance because it is free of any contaminants. Other
examples of pure substances are table salt, the aluminum in
sodacans, cooking oil, and diamond.

6. ELEMENTS
Elements are simple substances that have unique compositions.
They are composedof atoms, which can no longer be broken
downby either physical or chemical methods. Elements are the
building blocks of matter. Many elements are naturally
occurring, and only a few are synthesized inside the laboratory.
These elementscan be classified as metals, nonmetals, or
metalloids.

7. Take a look onthe pictures below and keenlyobserve each. What have you
noticed?

8. ELEMENTS
The pictures are materials that contain elements. Howdoyou
knowifasubstanceisanelement? An elementis a pure
substance that cannotbe brokendowninto simpler substances
but can be chemically combined with one another to produce
another substance. This makes elementsas a homogenous
example of matter.

9. ELEMENTS
Meaning whenyou cut a nail into pieces, it will still bea nail
that is made up of iron. This makes element as the main building
block of matter.
Properties of Elements
Elements could either have physical and chemical properties. To
showdistinction of elements found either free in nature or
artificial, hereare some of its physical and chemical properties
as pure substances.

10. Properties of Elements
Physical Chemical
Luster Flammability
Volume Oxidation
Color Toxicity
Mass Acidity
Shape Stability

11. Properties of Elements
When yousay physical, this is a property that can be readily
observedthrough the human senses.Examples wereshown on
Table 1 whereinone can easily notice such attributes by just
seeing and manipulating, thus acquiring thesequalities without
altering orchanging their composition. With the use of your
sense organs, you can easily identify these properties.

12. Properties of Elements
Chemical properties on the other hand are those properties that
can be attained once anelement undergoeschange in
composition suchas burning.
Physical Properties of Elements
1. Luster-shiny in appearance
2. Volume-amount of space occupied by an object

13. Properties of Elements
Physical Properties of Elements
3. Color-the aspect of the appearance of objects and light
sources.
4. Mass-theamount of material it contains
5. Shape-appearance or form of a sample matter

14. Properties of Elements
Chemical Properties of Elements
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 degreeof being poisonous
4. Acidity-the state of being acidic by nature

15. Properties of Elements
Chemical Properties of Elements
5. Stability-resistance to chemical change or to physical
disintegration

16. Pictures of some Elements