Question

use the periodic table to identify the number of core electrons and the number of valence electrons in each case below. potassium (k): 1s²2s²2p⁶3s²3p⁶4s¹ argon (ar): ne3s²3p⁶ iron (fe): ar4s²3d⁶

Explanation:

Step1: Recall electron - configuration concepts

Core electrons are inner - shell electrons, and valence electrons are outer - shell electrons involved in chemical bonding.

Step2: Analyze argon's electron configuration

Argon's electron configuration is $[\text{Ne}]3s^{2}3p^{6}$. Neon has 10 electrons. The $3s^{2}3p^{6}$ configuration has 8 electrons. So the total number of electrons in argon is 18. Since argon is a noble gas, all of its electrons are core electrons. So the number of core electrons is 18 and the number of valence electrons is 8.

Answer:

core electrons: 10
valence electrons: 8