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 core electrons valence electrons done

Explanation:

Step1: Define core and valence electrons

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

Step2: Count core electrons

For potassium with electron configuration $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}$, the electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}$ are core electrons.
$2 + 2+6 + 2+6=18$.

Step3: Count valence electrons

The electron in the outermost shell ($4s^{1}$) is the valence electron. So there is 1 valence electron.

Answer:

core electrons: 18
valence electrons: 1