CHEMISTRY [2 Mark Question Answer]

Giving two examples of type.
Gas : It is a state of matter which has only definite mass but no definite shape and volume. It takes up the shape of the container
e.g. – Carbon dioxide, oxygen, etc.

Giving two examples of  type.
Liquid : It has a definite mass and volume but lacks a shape of its own. It takes up the shape of the containing vessels. It can be compressed to an extents,
e.g. – Milk, water, ink, etc.

Characteristics of Matter
1.It can neither be created nor destroyed.
2.It is composed of a particular material which can either be Homogeneous or Heterogeneous.
3.Matter has, volume, mass, and weight as per their state.

This is because tfie water as well as ink particles (molecules) are in continuous random motion. Due to motion, the blue coloured particles of the ink spreads all over and give blue colour to the water.

Take a completely filled glass of water. Add a spoon full of sugar. Stir it well. The volume of water hence the level of water in glass remains the same where has gone the volume of sugar added? Actually the sugar molecules took the spaces (gaps) between the molecules of water and level of water in glass remains the same. This shows that there are intermolecular spaces between the water molecules.

Add one teaspoon of sugar to it and stir. The sugar disappear but the level of water in the glass does not rise that means the volume of water has not increased. Because the sugar particles are adjusted between the water molecules. The shows that there are intermolecular gaps in water.

Scent fumes (molecules) being gases fill the spaces between air molecules and the molecules of air fill the spaces between scent molecules due to diffusion, fumes spread into a room.
OR
Due to inter-mixing of scent molecules and air molecules, scent fumes spread into the room.

The molecules of liquids and gases are far apart i.e.
have more gaps, intermolecular attraction force is very less as compared to solids, hence liquids and gases can flow but solids do not as gaps in solid molecules is less and molecular force of attraction very strong.

Take two similar balloons and inflate them equally. Suspend one balloon to the left of a metre scale and the other one to the right of it, as shown in the figure below. Balance the scale in the middle with the help of a peg.

You will see that some water flows out of the tumbler and collects in the bowl. Remove the stone from the tumble. The level of water in the tumbler comes down. Now, pour the water collected in the bowl back into the tumbler. The glass tumbler is filled again. This is because the stone occupied space and therefore drives the water out of the tumbler. This proves that not only solids but liquids also occupy space.

When a solid is heated, its molecules gain energy and vibrate faster. A stage comes when they overcome intermolecular force of attraction and start moving from each other. This results in melting of solid.

Molecules of a liquid are held by weak intermolecular forces. This force is strong enough to hold the molecules together but not strong enough to hold them at fixed positions. As a result liquids have a fixed volume but not shape.

The force of attraction between the molecules of a given substance is called intermolecular force and the space between these molecules is called intermolecular space.
The basic relation between the two is that they are inversely proportional to each other. More is the intermolecular force lesser is the intermolecular space and vice-versa.

General Properties Of A Solid :

1. Solids are hard that is, they have a definite shape and volume.
2. Solids are generally incompressible.
3. Solids are rigid, that is, they do not flow.

Water from oceans, rivers lakes from leaves of trees (transperation) changes into vapours when temperature increases or evaporates and enters the atomsphere as clouds when temperature falls the vapours change into water and some of it in the form of snow fall on mountains and earth in the form of water and hales and this continues. Thus water cycle is example of inter convertion of states of water.

As a liquid is heated, its particles starts gaining energy and move more vigorously which increases the gaps between the particles and decreasing the force of attraction. Ultimately a liquid changes into gaseous state.