Arrange `H_2 , D_2 and T_2` in the decreasing order of their
(i) boiling points (ii) heat of fusion

Explanation

To solve the problem of arranging \( H_2 \), \( D_2 \), and \( T_2 \) in decreasing order of their (i) boiling points and (ii) heat of fusion, we will follow these steps:

### Step 1: Understand the Isotopes
- \( H_2 \) is molecular hydrogen, consisting of two hydrogen atoms.
- \( D_2 \) is deuterium, consisting of two deuterium atoms (a hydrogen isotope with one neutron).
- \( T_2 \) is tritium, consisting of two tritium atoms (a hydrogen isotope with two neutrons).

### Step 2: Determine Molar Masses
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