Question

3. An element reacts with oxygen to give a compound with a high melting point. This
compound is also soluble in water. The element is likely to be

(a) calcium
(b) carbon
(c) silicon
(d)iron
​

Answer 1

Answer:

An element is likely to be. calcium reacts with oxygen and forms calcium oxide which as high melting point and is soluble in water.

Answer 2

Answer:

a

Explanation:

If the product has a high melting point, then it is an ionic compound as well as an oxide. Since the oxides carbon and silicon are covalent compounds, then the choices b and c are wrong. iron and calcium both form ionic oxides, but the oxides of iron are insoluble in water, whereas calcium oxide is soluble in water. so the answer is a.