$20.0 \mathrm{dm}^3$ of an ideal gas ' X ' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa . Which of the following option is correct?

(Given: $\log 2=0.3010$ and $\log 5=0.6989$ )

In period 4 of the periodic table, the elements with highest and lowest atomic radii are respectively.

Method used for separation of mixture of products ( B and C ) obtained in the following reaction is

Regarding the hydrides of group 15 elements $\mathrm{EH}_3(\mathrm{E}=\mathrm{N}, \mathrm{P}, \mathrm{As}, \mathrm{Sb})$, select the correct statement from the following :

A. The stability of hydrides decreases down the group.

B. The basicity of hydrides decreases down the group.

C. The reducing character increases down the group.

D. The boiling point increases down the group.

Choose the correct answer from the options given below :