Question

An element has a mass number 4 and atomic number 2. Write the valency and symbol of this element​

Answer 1

Answer:

Valency is 0

Symbol is He.

Answer 2

Ur Answer:-

We know that only valence electrons take part in bond formation with different atoms.In the atom of 'X' element there are only two electrons since atomic number is 2. Thus, K shell is fully filled for this atom. Hence,its valency is zero.

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