Energy Changes

Question 1

Exothermic process or reaction in terms of energy

Answer 1

Heat energy is released to the surroundings.

Question 2

Exothermic process or reaction in terms of temperature change

Answer 2

Increase in temperature (becomes hotter).

Question 3

Examples of Exothermic process or reaction

Answer 3

1. combustion
2. rusting
3. respiration
4. freezing /condensation
5. bond formation
6. neutralisation

Question 4

Endothermic process or reaction in terms of energy

Answer 4

Heat energy is absorbed from the surroundings

Question 5

Endothermic process or reaction in terms of temperature

Answer 5

Decrease in temperature (becomes colder).

Question 6

Examples of Endothermic process or reaction

Answer 6

1. dissolving of ammonium nitrate in
   water
2. thermal decomposition: calcium carbonate →calcium oxide + carbon dioxide
3. photosynthesis
4. melting / evaporation/ boiling
5. bond breaking