Look at the next drawing please:
The three situations will be analyzed according to the drawing above:
1. Burning of wood is an exothermic reaction, therefore, it frees heat to the surroundings. => q (-)
2. An exothermic reaction releases heat, therefore is equal to 1. => q (-)
3. Melting of ice consumes heat. => endothermic => q (+)
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Answer: 1 and 2