1 States of Matter

Question 1

Define diffusion

Answer 1

Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, down a concentration gradient.

Question 2

Arrangement of particles in a solid

Answer 2

The particles in a solid are arranged in a fixed pattern. The strong forces of attraction holding them together prevent the particles from breaking away from their fixed positions. The particles can only make tiny vibrations to and fro.

Question 3

Arrangement of particles in a liquid

Answer 3

The particles in a liquid are close together but not in a fixed position. They can move about and slide past each other.

Question 4

Arrangement of particles in a gas

Answer 4

The particles in a gas are far apart and move about very quickly. There are almost no forces holding them together. The particles collide with each other and bounce off in all directions.

Question 5

Explain the process of melting

Answer 5

When a solid is heated, the particles gain heat energy and vibrate more, causing the solid to expand. At the melting point, the particles vibrate so much that they break away from their positions causing the solid to turn into liquid.

Question 6

Explain the process of boiling

Answer 6

When a liquid is heated, the particles gain heat energy and move faster. The particles collide with each other more frequently and bounce further apart causing the liquid to expand. At boiling point, the particles possess sufficient energy to overcome the forces of attraction between them, breaking away to form a gas.

Question 7

Explain the process of condensation

Answer 7

When a gas cools, its particles lose energy and move slower. When they collide, they do not posses sufficient energy to bounce away. Hence the particles stay close together and form a liquid.

Question 8

What causes the pressure in a gas?

Answer 8

1. Temperature of gas
2. Volume it takes up

Question 9

How does increasing temperature, increase gas pressure?

Answer 9

When temperature is increased, gas particles gain more heat energy and move faster. They collide with each other more frequently and bounce off with greater force, increasing the gas pressure.

Question 10

How does compressing gas into a smaller space, increase its pressure?

Answer 10

Since the particles are in a smaller space, they will collide with each other more frequently and bounce off with greater force, increasing the gas pressure.

Question 11

How does temperature affect rate of diffusion?

Answer 11

When a gas is heated, its particles gain heat energy and move faster. They collide more frequently and bounce further away causing the gas to diffuse faster. Hence the higher the temperature, the faster the rate of diffusion.