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CBSE Class 11-science Answered

Explain why helium molecule does not exist?
Asked by Topperlearning User | 08 Oct, 2014, 01:56: PM
answered-by-expert Expert Answer

Helium atom (1s2) has 2 electrons in its 1s orbital.

During the approach of two helium atoms, the repulsive forces are dominant over the attractive forces. As a result the energy of the system increases which leads to instability.

Since energy of the separate helium atoms is smaller than that of the system when they are close to each other, they prefer to stay separate and do not form He2 molecule.

Answered by | 08 Oct, 2014, 03:56: PM

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