Page 15 - ICSE Chemistry 8

1 Matter

Learning Outcomes Key Concepts
Students will be able to
• Matter
• describe the main postulates of the kine c molecular theory of ma er.
• Kinetic Molecular Theory
• explain the reason of change of one state of ma er to another and
of Matter
vice versa on the basis of interpar cle space, and interpar cle a rac on
and collision. • States of Matter Based on
Kinetic Molecular Theory
• defi ne and explain the law of conserva on of mass using an example.
• States of Matter
• Change of State of Matter
• Law of Conservation of
Mass

Warm Up Activity
Draw the diagrams of solids, liquids and gases showing the arrangement of par cles.

State the reason why the arrangement of par cles is diff erent in three states of ma er.
Solids: _______________________________________________________
Liquids: ______________________________________________________

Gases: _______________________________________________________

MATTER

Anything that has mass and occupies space is ma er.

Ma er is made of ny par cles called atoms. Usually, an atom cannot exist independently. Thus, atoms
combine to form molecules.
We have learnt in previous classes that ma er exists in three states: solid, liquid and gas.

Solids: Solids have fi xed shape and volume.
Liquids: Liquids have fi xed volume and they take the shape of the container which they are poured in.

Gases: Gases have no fi xed shape or volume. They take the shape and volume of the container they are
kept in.
Depending on the temperature and pressure, ma er can exist in any of these three forms.

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