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

The Element is likely to be Calcium (Option a)

Calcium react with oxygen and gives calcium oxide which has a high melting point of 2,572 celsius and it is also soluble in water

Let us look at other options :
Option b - carbon reacts with oxygen to give carbon dioxide which is a gas. So, this option is wrong.
Option c - silicon reacts with oxygen to form silicon oxide which is insoluble in water .So, the option is wrong
Option d - iron reacts with oxygen to form iron(iii) oxide which is insoluble in water.So,the option is wrong