NCERT Solutions for Chapter: Atoms and Molecules, Exercise 1: Exercise

An ion is always a single charged atom.

An ion of a metal is always positively charged.

An ion of a non-metal is either positively or negatively charged?

The incorrect formula among the following is:

The formula of a compound when a positive radical '$\mathrm{A}$’ with valency $2$ and negative radical ‘$\mathrm{B}$’ with valency $1$ combine is _____.

If the formula of a metal ion is ${\mathrm{M}}^{+2}$, then the formula of its dihydrogen phosphate is

Arrange the following points in a sequence for derivation of formulae of compounds.

1. The valencies of the ions or radicals are written below the radicals without positive and negative sign.
2. If the valencies have common factors, then they are divided by the highest common factor.
3. The magnitude of valencies should be interchanged and written as subscripts on the right side of the respective ions.
4. The positive radical followed by negative radical are written with their charges.
5. If the radicals have more than one atom, they are enclosed in brackets and the appropriate valency (more than one) is written as subscripts outside the bracket.

A non-metal X forms two oxides, A and B. The ratio of weight of the element X to the weight of oxygen in A and B is $7:20$ and $7:16$, respectively. If the molecular mass of the oxide, A is $108$, identify A and B.