Which of the following best explains why the atomic radius of gallium is smaller than that of aluminium?

1. Poor shielding effect of the 2d-electrons

2. Poor shielding effect of the 3d-electrons

3. Poor shielding effect of the 3p-electrons

4. Poor shielding effect of the 2s-electrons

Identify the pair in which both oxides are amphoteric in nature.

1. Tl₂O₃, SiO₂

2. ${\mathrm{CO}}_2$, ${\mathrm{B}}_2{\mathrm{O}}_3$

3. ${\mathrm{B}}_2{\mathrm{O}}_3$, ${\mathrm{SiO}}_2$

4. Al₂O₃ , PbO₂

When a metal X is treated with sodium hydroxide, a white precipitate (A) is obtained, which is soluble in excess of NaOH to give soluble complex (B). Compound (A) is soluble in dilute HCl and forms compound (C). The compound (A) when heated strongly gives (D), which is used to extract the metal.

X, C & D are respectively :

An aqueous solution of Borax is-

The hybridization of boron in diborane is-

1. sp

2. s${\mathrm{p}}^2$

3. s${\mathrm{p}}^3$

4. ds${\mathrm{p}}^2$

Find the thermodynamically most stable allotrope of carbon.

Identify the statement that incorrectly describes the preparation of carbon monoxide or carbon dioxide.

When hydrated alumina is treated with an aqueous NaOH solution, it gives-

1. ${\mathrm{NaAlO}}_2$

2. $\mathrm{Na}\left({\mathrm{Al}}_2{\mathrm{O}}_3\right)$

3. ${\mathrm{NaAl}}_2\mathrm{O}$

4. Both (2) and (3)

The correct reaction(s) among the following options is/are -

1. ${\mathrm{SiO}}_2$ $+\hspace{0.17em}4\mathrm{HF}$ $\to$ ${\mathrm{SiF}}_4$ $+$ $2{\mathrm{H}}_2\mathrm{O}$

2. $\mathrm{ZnO}$ $+$ $\mathrm{CO}$ $\to$ $\mathrm{Zn}$ $+\hspace{0.17em}{\mathrm{CO}}_2$

3. ${\mathrm{SiF}}_4$ $\hspace{0.17em}+$ $2\mathrm{HF}$ $\to$ ${\mathrm{H}}_2{\mathrm{SiF}}_6$

4. All of the above

Identify the incorrect statement regarding allotropes/ allotropy.