IMAT 2017 Q50 [Identity of Element X]

Element X is a grey solid.

It combines with chlorine to form a polar molecule with the formula XCl . In this compound, element X has an oxidation state of +1.

In potassium iodide solution, it dissolves to form a coloured solution.

At 500 °C, it becomes a coloured vapour.

What is the identity of element X?

A. manganese
B. fluorine
C. iodine
D. carbon
E. lithium