Question

An element 'X' has a valency 3: Write the chemical formula of its phosphide. Write the chemical formula of its carbonate. Is element 'X' a metal or non-metal? "Please explain the answers also!"

Answer 1

Symbol                           X                  P

Valency                          3                    3-

So , by criss cross method ,Chemical  formula = XP

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Symbol                          X           CO₃

Valency                          3              2

So , by criss cross method , chemical formula = X₂ (CO₃)₃
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X is a metal.

The elements with valency less than 5 are known as metals.

The elements with valency more than or equal to 5 are known as non -metals.

The elements with valency zero are noble gases / inert gases