Element X forms a chloride with the formula XCl2, which is a solid with high melting point. X would most likely be in the same group of periodic table as
Mg
Correct Answer: (c) Mg
Explanation: Magnesium (Mg) forms a chloride with the formula MgCl2 and is in the same group of the periodic table as Element X, both being alkaline earth metals.
Which of the following numbers represent the atomic mass of calcium?