The correct order of ionic character among CaH₂, BeH₂ and BaH₂ is:

1. ${\mathrm{BeH}}_2<{\mathrm{CaH}}_2<{\mathrm{BaH}}_2$

2. ${\mathrm{CaH}}_2<{\mathrm{BeH}}_2<{\mathrm{BaH}}_2$

3. ${\mathrm{BeH}}_2<{\mathrm{BaH}}_2<{\mathrm{CaH}}_2$

4. ${\mathrm{BaH}}_2<{\mathrm{BeH}}_2<{\mathrm{CaH}}_2$

The species, having bond angles of 120° is : 

1. PH₃ 

2. ClF₃

3. NCl₃

4. BCl₃

Which of the following pairs of compounds is isoelectronic and isostructural?
(1) BeCl_2, XeF₂
(2) Tel_2, XeF₂
(3) ${\mathrm{IBr}}_2^{-}$_, XeF₂
(4) IF₃, XeF₂

Which one of the following pairs of species have the same bond order?

(1) CO, NO

(2) O_2-  , CN-

(3) CN- , NO+

(4) N+ , CN+

Which of the following species has a bond angle of \(120^\circ\)?
1. \(\mathrm{{SF}_6}\)
2. \(\mathrm{NCl_3}\)
3. \(\mathrm{BCl_3}\)
4. \(\mathrm{PH_3}\)

Which of the following pairs of species have the same bond order?

1. $O_2^{-},N{O}^{+}$

2. $C{N}^{-},CO$

3. $N_2,<mspace\; width="1em"></mspace>O_2^{-}$

2. CO, NO

Which of the following pairs share both isoelectronicity and isostructural characteristics?

${\mathrm{NO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{-2},<mspace\; width="1em"></mspace>{\mathrm{ClO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{SO}}_3$

1. ${\mathrm{NO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{-2}$

2. ${\mathrm{SO}}_3,<mspace\; width="1em"></mspace>{\mathrm{NO}}_3^{-}$

3. ${\mathrm{ClO}}_3^{-},<mspace\; width="1em"></mspace>{\mathrm{CO}}_3^{-2}$

4. ${\mathrm{CO}}_3^{-2},<mspace\; width="1em"></mspace>{\mathrm{ClO}}_3^{-}$

In which of the following compounds is an intramolecular hydrogen bond present?