Among CaH₂, BeH₂, and BaH₂  the order of ionic character 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 °?

$1.$ $S{F}_6$
$$
$2.$ $NC{l}_3$
$$
$3.$ $BC{l}_3$
$$
$4.$ $P{H}_3$

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

1. $O_2^{-},N{O}^{+}$

2. $C{N}^{-},CO$

3. $N_2, O_2^{-}$

2. CO, NO

Which of the following are isoelectronic and isostructural?

${\mathrm{NO}}_3^{-}, {\mathrm{CO}}_3^{-2}, {\mathrm{ClO}}_3^{-}, {\mathrm{SO}}_3$

(1) ${\mathrm{NO}}_3^{-}, {\mathrm{CO}}_3^{-2}$

(2) ${\mathrm{SO}}_3, {\mathrm{NO}}_3^{-}$

(3) ${\mathrm{ClO}}_3^{-}, {\mathrm{CO}}_3^{-2}$

(4) ${\mathrm{CO}}_3^{-2}, {\mathrm{ClO}}_3^{-}$

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

1. H₂O₂                                 

2. HCN

3. Cellulose                             

4. Concentrated acetic acid