How do Metals and Non - Metals React?

Of the three metals $\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z} , \mathrm{X}$ reacts with cold water, $\mathrm{Y}$ with hot water and $\mathrm{Z}$ with steam only. Identify $\mathrm{X} , \mathrm{Y}$ and $\mathrm{Z}$ and also arrange them in order of increasing reactivity.

Explain the following: 

NaCl is not a conductor of electricity in solid state whereas it does conduct electricity in aqueous solution as well as in molten state. 

A non-metal $\mathrm{A}$ which is the largest constituent of air, when heated with ${\mathrm{H}}_2$ in $1:3$ ratio in the presence of catalyst (Fe) gives a gas $\mathrm{B}$. On heating with ${\mathrm{O}}_2$ it gives an oxide $\mathrm{C}$. If this oxide is passed into water in the presence of air, it gives an acid $\mathrm{D}$ which acts as a strong oxidising agent.

 Identify $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and $\mathrm{D}$.

The electronic configurations of three elements $\mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ are $\mathrm{X}-2 , 8 ; \mathrm{Y}-2 , 8, 7$ and $\mathrm{Z}-2 , 8, 2$. Which of the following is correct?

Reaction between $\mathrm{X}$ and $\mathrm{Y}$, forms compound $\mathrm{Z}$. $\mathrm{X}$ loses electron and $\mathrm{Y}$ gains electron. Which of the following properties is not shown by $\mathrm{Z}$?

Which one of the following properties is not generally exhibited by ionic compounds?

Which of the following are not ionic compounds?

(i) $\mathrm{KCl}$

(ii) $\mathrm{HCl}$

(iii) ${\mathrm{CCl}}_4$

(iv) $\mathrm{NaCl}$