Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R

Assertion A : Hydrogen is an environment friendly fuel.

Reason R : Atomic number of hydrogen is 1 and it is a very light element.

In the light of the above statements, choose the correct answer from the options given below :

Resonance in carbonate ion $$\left(\mathrm{CO}_{3}{ }^{2-}\right)$$ is

Which of the following is true?

Which of the following represents the lattice structure of $$\mathrm{A_{0.95}O}$$ containing $$\mathrm{A^{2+},A^{3+}}$$ and $$\mathrm{O^{2-}}$$ ions?

Choose the correct statement(s) :

A. Beryllium oxide is purely acidic in nature.

B. Beryllium carbonate is kept in the atmosphere of $$\mathrm{CO_2}$$.

C. Beryllium sulphate is readily soluble in water.

D. Beryllium shows anomalous behaviour.

Choose the correct answer from the options given below :