Chapter 1 Matter in Our Surroundings
❖ Matter :- Matter is anything which occupies space and has mass is called matter.
Notes:-
1. Matter is made up of very small tiny particles.
2. Particles of matter have space between them they attract each other.
❖ The forces of attraction between the particles are maximum in solids,
intermediate in liquids and minimum in gases.
❖ Classification- On the basis of physical properties
1. Matter is classified as solids, liquids and gases.
2. On the basis of chemical properties, matter is classified as elements,
compounds and mixtures.
3. Solids- Solids have strong molecular force and a definite shape and size
solids can neither flow nor be compressed.
4. Liquids- Liquids have weak intermolecular flow and large intermolecular
spaces. Liquids do not have a definite shape but can flow.
5. Gases- Gases have weak intermolecular flow, high compressibility, and no
definite shape and volume.
❖ The difference in the characteristics of the three states of
matter.
Characteristics Solid Liquid Gas
Shape Fixed shape No fixed shape No fixed shape
Volume Fixed volume Fixed volume No fixed
volume
, Intermolecular Maximum Less than solids Very less
Intermolecular Very less More than Maximum
space solids
Rigidity/Fluidity Rigid/cannot Can flow/not Can flow/not
flow rigid rigid
Compressibility negligible compressible Highly
compressible
❖ Rigidity: It is the propensity of a substance to continue to remain in its
shape when treated with an external force.
❖ Compressibility:- Compressibility is the measure of how much a given
volume of matter decreases when placed under pressure.
❖ Fluidity :- It is the tendency of a substance to flow. Liquids and gases
possess fluidity while solids are rigid.
❖ Kinetic energy:- the energy of a body during its motion is called kinetic
energy.
❖ Filling of a gas container:- Gases have particles which vibrate randomly
in all the directions. The gas can fill the container.
❖ Shape:- Solids have maximum intermolecular force and definite shape.
❖ Density:- Density is the measurement of how tightly a material is packed
together. It is defined as the mass per unit volume.
❖ SI unit of density :- kilograms per cubic meter (kg/m3).
❖ Matter :- Matter is anything which occupies space and has mass is called matter.
Notes:-
1. Matter is made up of very small tiny particles.
2. Particles of matter have space between them they attract each other.
❖ The forces of attraction between the particles are maximum in solids,
intermediate in liquids and minimum in gases.
❖ Classification- On the basis of physical properties
1. Matter is classified as solids, liquids and gases.
2. On the basis of chemical properties, matter is classified as elements,
compounds and mixtures.
3. Solids- Solids have strong molecular force and a definite shape and size
solids can neither flow nor be compressed.
4. Liquids- Liquids have weak intermolecular flow and large intermolecular
spaces. Liquids do not have a definite shape but can flow.
5. Gases- Gases have weak intermolecular flow, high compressibility, and no
definite shape and volume.
❖ The difference in the characteristics of the three states of
matter.
Characteristics Solid Liquid Gas
Shape Fixed shape No fixed shape No fixed shape
Volume Fixed volume Fixed volume No fixed
volume
, Intermolecular Maximum Less than solids Very less
Intermolecular Very less More than Maximum
space solids
Rigidity/Fluidity Rigid/cannot Can flow/not Can flow/not
flow rigid rigid
Compressibility negligible compressible Highly
compressible
❖ Rigidity: It is the propensity of a substance to continue to remain in its
shape when treated with an external force.
❖ Compressibility:- Compressibility is the measure of how much a given
volume of matter decreases when placed under pressure.
❖ Fluidity :- It is the tendency of a substance to flow. Liquids and gases
possess fluidity while solids are rigid.
❖ Kinetic energy:- the energy of a body during its motion is called kinetic
energy.
❖ Filling of a gas container:- Gases have particles which vibrate randomly
in all the directions. The gas can fill the container.
❖ Shape:- Solids have maximum intermolecular force and definite shape.
❖ Density:- Density is the measurement of how tightly a material is packed
together. It is defined as the mass per unit volume.
❖ SI unit of density :- kilograms per cubic meter (kg/m3).
