Elements are pure substances made of one kind of atom and are represented by chemical symbols. Compounds are made up of two or more elements chemically combined, represented by chemical formulas, while mixtures are physically combined substances whose properties remain unchanged. Mixtures can be separated by physical means and lack a fixed composition, unlike compounds which have distinct properties and fixed ratios.

1. ELEMENTS, COMPOUNDS
& MIXTURES

2. WHAT ARE ELEMENTS ?
ELEMENT :
 is a substance made up of only one kind of atom.
 are represented by chemical symbols.
 The smallest particle is atom
 118 elements are known.

3. EXAMPLES OF ELEMENTS
DIAMOND COPPER NEON GAS

4. WHAT ARE COMPOUNDS?
COMPOUND :
 is a substance made up of two or more
elements chemically combined together.
 represented by chemical formula.
 The smallest particle is molecule

5. SOME COMMON COMPOUNDS
WITH THEIR FORMULAE
COMPOUND CHEMICAL FORMULA
Silicon dioxide (Sand) SiO2
Sodium hydroxide (Caustic Soda) NaOH
Ethane C2H6
Calcium oxide (Quick Lime) CaO
Calcium carbonate (Lime Stone) CaCO3
Urea NH2CONH2
Benzene C6H6

6. SOME COMMON COMPOUNDS
Silicon Dioxide (sand)
SiO2

7. SOME COMMON COMPOUNDS

8. SOME COMMON COMPOUNDS
Sodium hydroxide
(Caustic Soda)
NaOH

9. SOME COMMON COMPOUNDS
Ethane
C2H6

10. SOME COMMON COMPOUNDS
Calcium oxide (Quick Lime)
CaO

11. SOME COMMON COMPOUNDS
Calcium carbonate
(Lime Stone)
CaCO3

12. SOME COMMON COMPOUNDS
Urea
NH2CONH2

13. SOME COMMON COMPOUNDS
Benzene C6H6

14. WHAT ARE MIXTURES ?
MIXTURE :
 is an impure substance made up of two or more elements
physically combined together.
 can be broken down by physical means.
 no chemical changes take place.
 substances held together by physical forces.
 The properties of an elements in a mixture remain same.
 has no formula.

15. TYPES OF MIXTURES
THERE ARE TWO MAJOR TYPES OF MIXTURES:
HETEROGENEOUS HOMOGENEOUS
Means “different” Means “the same”

16. TYPES OF MIXTURES

17. TYPES OF MIXTURES

18. MIXTURES VS. COMPOUNDS
COMPOUNDS MIXTURES
DEFINITION It is formed by the chemical
combination of atoms of the
elements.
Mixture is formed by the
simple mixing up of the
substances.
PROPERTIES In compounds the elements
lose their original properties
and form new substances
which are entirely different
from them.
In mixtures the properties of
an element remain same.
COMPOSITION Compounds always have a
fixed composition by mass.
Mixtures do not have fixed
composition.
JOINED OR NOT The components cannot be
separated by physical means.
The components can be
separated by physical methods.
MELTING POINTS Compounds have sharp and
fixed melting points.
Mixtures do not have sharp
and fixed melting points.

28. Thank you for
listening and
cooperating. 
Ma’am Anne~