state of matter

Question 1

How are particles represented in the particle mode?

Answer 1

by small solid spheres

Question 2

In solids the particles…..

Answer 2

• have a regular arrangement
• are very close together
• vibrate about fixed positions

Question 3

why are solids very close together in fixed positions to form a very regular lattice arrangement?

Answer 3

because there are strong forces of attraction between the particles

Question 4

the hotter a solid becomes the more they_______

Answer 4

vibrate

Question 5

the describe features of liquids

Answer 5

• have a random arrangement
• are close together
• flow around each other

Question 6

Why do liquid particles flow around each other?

Answer 6

because there’s weak force of attraction between particles

Question 7

liquid particles constantly move with what type of motion?

Answer 7

random motion

Question 8

the hotter the liquid get the _______ it moves

What does this cause the liquid to do?

Answer 8

faster

this causes the liquid to expand slightly when heated

Question 9

In gases the particles :

Answer 9

• have a random arrangement
• are much further apart
• move very quickly in all directions

Question 10

why are gas particles much further apart?

Answer 10

because they have a very weak force of attraction

Question 11

the hotter gas gets the ________ it moves

What does this cause the gas to do?

Answer 11

faster

gases either expand when heated or their pressure increases

Question 12

What happens when a substance changes state?

Answer 12

• the particles themselves stay the same
• the way the particles are arranged changes
• the way the particles move changes

Question 13

when does melting and freezing happen

Answer 13

at the melting point

Question 14

when does boiling and condensing happen

Answer 14

at the boiling point

Question 15

A pure substane will :

boiling and melting points

Answer 15

• melt and freeze at the melting point

- boil and condense at the boiling point

Question 16

What does the amount of energy required for a substance to change depend on?

Answer 16

the amount of energy required to overcome the forces of attraction between the particles

Question 17

the stronger the forces of attraction :

Answer 17

• the greater the amount of energy needed to overcome them

- the higher the melting point and boiling point will be

Question 18

What are examples of substances that have high melting points due to strong bonds?

Answer 18

ionic compounds, metals and giant covalent structures

Question 19

In substances that contain simple molecules:

Answer 19

• the bonds within the molecules are strong covalent bonds
• the forces of attraction between the molecules are much weaker
• only a little energy is needed to overcome the forces between the molecules, so the melting and boiling points are relatively low

Question 20

What are the limitations of the particle model?

Answer 20

It doesn’t take into account:

• the forces between the particles
• the volume of the particles
• the space between particles