1. Energy Changes
Do as a demo if necessary.

2. Combustion of a match
It is clear that heat and light are being released. So where does all that energy come from.

3. The conservation of energy: Energy cannot be created or destroyed
The conservation of energy: Energy cannot be created or destroyed. It can only be transferred between energy stores. In chemistry: All chemical reactions involve a change in energy. But that energy is neither created nor destroyed. It is transferred from or to the surroundings.

4. Respiration and photosynthesis
Make sure the reaction scheme has the key labels involving energy in and energy out

5. In exothermic reactions, energy is released to the surroundings and its temperature increases
In endothermic reactions, energy is taken in from the surroundings and its temperature decreases

6. Exothermic
Endothermic
Energy
Released to surroundings
Taken in from surroundings
Temperature of surroundings
Increases
Decreases
Examples
Combustion, respiration, self-heating cans, hand warmers
Thermal decomposition, citric acid and sodium hydrogen carbonate, sports related cold-packs

7. A solid + a liquid where the temperature changes from:
Generally students will say that the second one is endothermic as the temperature of the actual chemical is dropping. What is key here is that the temperature change is the temperature of the thermometer, which IS the surroundings. So if the thermometer is dropping, the surroundings must be losing energy so it must be endothermic.
A thermometer jammed into a piece of wool. When I add a certain chemical to it the temperature changes from:
20°C  5°C
A solid + a liquid where the temperature changes from:
20°C  40°C

8. Questions 1-6 from the mastery booklet
If you finish the questions start reading the next section

9. Measuring the change

11. Questions 7-18

12. Reaction profiles

14. Answer Q19 and the challenge question

15. Bond energy/enthalpy

16. H H O O H H
Molecules are stable – all atoms have full outer shells as they are bonded together
Step 1: Atoms need to be pulled away from each other. This requires energy so is endothermic H O H O
For this reaction, the amount of energy going in to step 1 is less than the amount released in step 2. The overall reaction is therefore exothermic.
Step 2: New bonds are formed. This process is exothermic

17. Breaking bonds requires energy to be put in. It is endothermic
Making bonds releases energy to the surroundings. It is exothermic

18. Calculating the change – page 118 in your text book

19. Worked examples from booklet
Answer questions 20-30

20. Working out the overall energy change
Hydrogen + water
Nitrogen + hydrogen

22. Complete mastery booklet