Q3 of 75 Page 57

Give symbol and valency of the following ions.
Hydroxide ion, carbonate ion.

Hydroxide ion:

Symbol of hydroxide ion = OH^-

Valency = -1

Carbonate ion:

Symbol of carbonate ion = CO₃^2-

Valency = -2

How is an ion different from an atom? How is cation different from anion?

Predict the total number of atoms in each case.

(i) Calcium phosphate

(ii) Hydrogen sulphide

(iii) Magnesium bromide

(iv) Sodium oxide

(v) Aluminium hydroxide

What is the role of valency in the combination of atoms?

An element X forms X₂(CO₃)₃ type compound. What is the formula of its phosphate and chloride?

Give symbol and valency of the following ions.Hydroxide ion, carbonate ion.