Matter

Introduction

Matter

Anything which occupies space and has mass is called "matter".

Eg. Air, silver , still, table , chair etc.

Characteristics of Matter

Things around us are composed of different kinds of materials. In the same material same type of molecules are found such as in case of ice , water molecules are present.

(1) Matter occupies the space

The volume is the amount of space occupied by the material.

(2) Matter has mass

Any kind of material visible and invisible , has certain amount of matter in it called as "mass"

Structure and composition of matter

Matter is made up of very very small particles in it.

These particles which make up the matter are atoms, ions and molecules

  • Atoms - It consist of nucleus which is positive charge at centre and electrons which possesses negative charge as in cloud around it. In case of sodium and helium they presence in combine form as lack of individual existence to fprm molecules.
  • Molecules - These are the smallest distinct units in to which a pure matter is devided. they represent the chemical and composition property of matter. Combination of two or more atoms result in formation of molecule. Combine atoms may be of one kind or different. Water is made up of hydrogen and oxygen where hydrogen molecule is made up of two hydrogrn atoms.
  • Ions - It may be positive or negative with respect to atoms or groups of atoms. Atom or group of atom transformed to form ions when they lose or gain the one or more electron. Eg. sodium ion , chlorine ion

States of matter

Intermolecular force of attraction and intermolecular space are two important properties of matter. If the intermolecular force of attraction increases, the molecules come closer , thus intermolecular space decreases and if the space increases. This fact accounts for the different states of matter. Matter exist in three different states i.e. as solid , liquid and gas.

 

Task

1. what do you mean by matter?

2. What are the characteristics of particles of matter?

3. Liquid generally have lower density as compared to solids. But you must have observed that ice floats on water . Find out why?

4. For any substance , why does the temperature remain constant during the change of state?

Process

 

Evaluation

1. Which one is a kind of matter?

    (a) Light  (b) Petrolium (c) Sound (d) Heat

2. The state of matter which has no definite shape or volume is called

    (a) Solid (b) Liquid (c) gas (d) water 

3. A kind of matter which sublime is 

    (a) water (b) plastic (c) milk (d) Iodine 

4. A substance which can change its state

    (a) wood (b) oxygen (c) paper (d) cloth 

Conclusion

These videos and task will help you in coming examination so make sure you watch the video carefully. You have 5 days to complete the class activity and your activity is due on the 17 september.

Good Luck