In ${\mathrm{PO}}_4^{3-}$ ion, the formal charge on the oxygen atom of the P-O bond is : 

In ${\mathrm{NO}}_3^{-}$ ion, the number of bond pairs and lone pairs of electrons on the nitrogen atom is

1. 2, 2

2. 3, 1

3. 1, 3

4. 4, 0

Which of the following attain the linear structure?

(a) ${\mathrm{BeCl}}_2$

(b) ${\mathrm{NCO}}^{+}$

(c) ${\mathrm{NO}}_2$

(d) ${\mathrm{CS}}_2$

Choose the correct option

1. (a), (d)

2. (b), (c)

3. (c), (d)

4. (b), (d)

CO is isoelectronic with

(a) ${\mathrm{NO}}^{+}$

(b) ${\mathrm{N}}_2$

(c) ${\mathrm{SnCl}}_2$

(d) ${\mathrm{NO}}_2^{-}$

Choose the correct option

1. (a), (b)

2. (b), (c)

3. (c), (d)

4. (b), (d)

Among the following, the correct statements about ${\mathrm{CO}}_3^{2- }$

Choose the correct option

1. (a), (b)

2. (b), (c)

3. (c), (d)

4. (b), (d)