Practice Valence Electron in Chemistry

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

An electron residing in the outermost (highest-energy) occupied shell of an atom, available for participation in chemical bonding through sharing, gaining, or losing.

The electrons that 'reach out' to other atoms. These do the bonding.

Example 1

easy
How many valence electrons does nitrogen (Z = 7) have?

Example 2

medium
Explain why elements in Group 17 (halogens) are highly reactive, using the concept of valence electrons.

Example 3

easy
Determine the number of valence electrons for: (a) carbon, (b) sulfur, (c) argon.

Example 4

medium
Sodium has electron arrangement 2,8,1. How many valence electrons does it have, and is it more likely to lose one electron or gain seven?
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