According to valence bond theory, the minimum of the potential energy curve describing the interaction of h atoms in h2 corresponds to

The interaction between the two atoms of H in H2 with the lower energy corresponds to a covalent bond between hydrogen's.

When the two atoms of H form a bond, they are overlapping the individual orbitals to form a new one. Every hydrogen has 1 electron which sits in a 1s orbital and then form one molecular orbital. The energy of H2 is lower than individual hydrogens because the electrostatic interaction between them.

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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