Changes of State Levels

Question 1

3 states of matter:

Answer 1

• solids
• liquids
• gases

Question 2

Describe the arrangement of solids and the motion of the particles

Answer 2

• particles close together
• regular pattern of particles
• have a fixed shape
• vibrate on the spot
• cannot be compressed or squashed

Question 3

Describe the arrangement of liquids and the motion of the particles

Answer 3

• particles close together
• random arrangement of particles
• flow and take the shape of the container
• move around each other
• cannot be compressed or squashed

Question 4

Describe the arrangement of gases and the motion of the particles

Answer 4

• far apart (the particles)
• random arrangement of particles
• flow and COMPLETELY fill their container
• move quickly in all directions
• can be squashed or compressed

Question 5

Explain what happens to bonds during melting and vaporisation and why there is no rise in temperature during the change of state – even though energy enters the system.

Answer 5

• the movement of the particles increase
• bonds between particles break when the substance melts or evaporates to form a gas from a solid
• a rise in heat results in an increase in internal change
• heat energy is used to change the bonding between the molecules
• in melting, added energy is used to break the bonds between the molecules
• the energy exchanges are NOT transferred into kinetic energy

Question 6

Explain what happens to bonds during condensation and freezing and why there is no rise in temperature – even though energy leaves the system.

Answer 6

• the movement of particles decrease
• bonds between particles form when a substance condenses or freezes to form a solid from a gas
• A decrease in heat results in a decrease in internal change
• in the case of freezing, energy is subtracted as the molecules bond to one another
• energy exchanges are not changes in kinetic energy but changes in bonding energy between the molecules