Sure, let's classify each given process as either endothermic or exothermic:
1. Burning a candle:
- When a candle burns, it releases light and heat into the surroundings. This release of energy is characteristic of exothermic processes.
- Therefore, burning a candle is an exothermic process.
2. Cooking an egg:
- Cooking an egg requires the absorption of heat from an external source, like a stove, to cause the chemical changes needed to cook the egg.
- Hence, cooking an egg is an endothermic process.
3. Rain changing to snow:
- When rain changes to snow, the water molecules release energy as they transition from a liquid state to a solid state, resulting in the release of heat.
- Thus, rain changing to snow is an exothermic process.
4. Boiling water:
- Boiling water requires continuous input of heat to convert the water from liquid to gas.
- Therefore, boiling water is an endothermic process.
5. Combustion reaction (CH₄ + 2 O₂ → CO₂ + 2 H₂O + heat):
- Combustion reactions release energy in the form of heat and light as chemical bonds are broken and formed.
- So, the combustion reaction is an exothermic process.
To summarize:
Burning a candle: exothermic
Cooking an egg: endothermic
Rain changing to snow: exothermic
Boiling water: endothermic
Combustion reaction: exothermic
