MEDIUM
Lower Secondary Stage 9
IMPORTANT
Earn 100
Match each change of state with its energy change.
Change of state: Melting, freezing, condensing, evaporating
Energy change: Exothermic, Endothermic.
Important Questions on Energy Transfers in Chemistry
MEDIUM
Lower Secondary Stage 9
IMPORTANT
Explain how sweating cools the skin.
Energy transfers from the skin to sweat as ______. A moisture leaves the skin _____ , it carries a lot of heat with it, cooling your body.
MEDIUM
Lower Secondary Stage 9
IMPORTANT
The diagram shows a burring candle.
Describe what happens to the wax as the candle burns.
MEDIUM
Lower Secondary Stage 9
IMPORTANT
When wax burns is the reaction exothermic or endothermic? Give a reason for your answer.
MEDIUM
Lower Secondary Stage 9
IMPORTANT
Safi has drawn a sketch graph to show how the temperature of the wax changes as the candle burns. Explain why there is a plateau in the graph.
