Question

1. The maximum number of electrons that can be present in M shell is _________


2. The sum of number of protons and neutrons in an atom is called as _________


3. The protons and neutrons are collectively known as __________


4. Elements having completely filled outermost shell have _______ valency.

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Answer 1

Answer:

1. 18

2. Mass number

3. Nucleons

4. zero

Explanation:

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