Question 8.
Explain the following:
In cold regions in winter, the rocks crack due to anomalous expansion of water.
Answer:
Anomalous expansion: Water contracts when heated from 0° to 4°C (instead of expanding) and water expands when cooled from 4°C to 0° This expansion of water from 4°C to 0° C is called anomalous expansion of water.
(i) In colder seasons, the temperature drops to 4°C.This means water starts to expand.
(ii) As there is no place for the water to expand inside the rocks, it exerts a high pressure on the rocks.
(iii) As a result, the rocks break.
