Catenation i.e., linking of similar atoms depends on the size and electronic configuration of atoms. The

the tendency of catenation in group 14 elements follows the order-

1.  $\mathrm{C}>\mathrm{Si}>\mathrm{Ge}>\mathrm{Sn}$

2.  $\mathrm{C}>>\mathrm{Si}>\mathrm{Ge}\approx \mathrm{Sn}$

3.  $\mathrm{Si}>\mathrm{C}>\mathrm{Sn}>\mathrm{Ge}$

4.  $\mathrm{Ge}>\mathrm{Sn}>\mathrm{Si}>\mathrm{C}$

Dry ice is-

1. Solid NH₃

2. Solid SO₂

3. Solid CO₂

4. Solid N₂