This compound is also soluble in water. The element is likely to be

(a) Calcium

(b) Carbon

(c) Silicon

(d) Iron

Answer:

Correct answer is option (a) i.e Calcium.

Calcium oxide is formed when calcium combines with oxygen. Calcium Hydroxide is formed when calcium oxide is dissolved in water.
Option B is incorrect since carbon creates carbon-oxide with oxygen, which is a gas.
Silicon dioxide is formed when silicon combines with oxygen. This substance is water-insoluble. As a result, option C is incorrect.
Iron generates Iron dioxide when it combines with oxygen. This substance is water-insoluble. As a result, option D is incorrect.