If an element contains 8 electrons how many electrons will be placed in the 2nd valence shell?

The number of electrons that will be placed in the second valence shell is 6 electrons

From a background understanding of the arrangement of electrons around the nucleus of atom, we understood that the 1st shell will hold a maximum of 2 electrons, while other shells a maximum of 8 electrons.

Considering the question given above, we have:

Total electron = 8 electrons

Remaining electrons = 8 – 2

Since the remaining elections is not more than 8 electrons, they will be place in the 2nd shell i.e

Thus, we can conclude that the 2nd shell will have 6 electrons.

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we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).