Download Class- VII Matter

THE HERITAGE SCHOOL
CHEMISTRY
SUPPLEMENT- 1
CLASS- VII
CHAPTER- MATTER
Matter :Anything that has mass,occupies space and can be perceived by our senses
is called matter.example:sugar,water,gold, nitrogen.
The quantity of matter that a body contains is called mass.
The space occupied by a body is called volume.
Composition of matter:Matter is composed of small particles –molecules,atoms
or ions.
Concept of atoms and molecules:
Atom is the smallest particle of matter which may or may not exist independently
but exhibits all the properties of matter.
Molecule is the smallest particle of matter which exist independently and exhibits
all the properties of matter.
Characteristics of particles of matter:
1. All matter is made up of minute particles called atoms or molecules which are
in a continuous random motion.
2. Particles of matter have space between them called intermolecular space .This
space is minimum in solids and maximum in gases.
3. There exists a force of attraction between the particles which is known as
intermolecular force of attraction.this force of attraction is maximum in solids and
minimum in gases.
All matter exists in three states generally-solid ,liquid,gas.
Interconversion of states of matter.
Interconversion of states of matter is the process by which matter changes from
one form to another and back to the original state without any change in its
chemical composition,when conditions are changed.
Cause of change of state:
1.change of temperature
2.change of pressure.