Question

A gray solid when heated vaporised to form pure white crystals on the cooler parts of the test tube and heavily, black solid as the residue. It is likely that the original solid is :

• A. an element
• B. a metal
• C. a pure compound
• D. a mixture

Answer 1

The correct option is D a mixture

Heating is a physical means to separate a mixture of two substances which are not chemically together as in a compound so they are separated by heating.