Question

(Assertion) On reacting with water, calcium starts floating over water.

(Reason) Calcium reacts with cold water at room temperature.
​

Answer 1

Answer:

Assertion: Calcium floats over water during reaction with water. Reason: Calcium reacts with water less vigorously so that heat evolved is not sufficient for the hydrogen formed, to catch fire. The bubbles of hydrogen gas formed stick to the surface of the water calcium

Answer 2

Both the Assertion and Reason are true but Reason is not the correct explanation of the Assertion.

CHEMICAL PROPERTY OF CALCIUM -

• A chemical element with the atomic number 20 and is one of the alkaline earth metals.
• Highly reactive in nature and reacts with both air and water.
• Calcium reacts with cold water to form calcium hydroxide with the release of hydrogen gas.
• The heat released is not enough to catch fire, therefore, hydrogen gas bubbles formed stick to the surface of the element.
• Due to this, the calcium seems to float on the water surface.