Question

based on the electron configuration, how many valence electrons are in calcium, ca? 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4 2 20 1

Explanation:

Step1: Identify valence shell

Valence electrons are in the out - most shell. For calcium with electron configuration $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}$, the out - most shell is the 4th shell.

Step2: Count electrons in valence shell

In the 4th shell ($4s^{2}$), the number of electrons is 2.

Answer:

2