Question

question 6 of 10
potassium (k) has an atomic number of 19. it often forms an ion by losing 1
electron. how many electrons would the ion have?
a. +1
b. -1
c. 18
d. 20

Explanation:

Step1: Recall the relationship between atomic number and electrons in a neutral atom

The atomic number of an element is equal to the number of protons and also the number of electrons in a neutral atom. For potassium (K), atomic number \(Z = 19\), so a neutral K atom has \(19\) electrons.

Step2: Consider the effect of losing an electron

When an atom loses an electron, the number of electrons decreases. If a K atom loses \(1\) electron, the number of electrons in the ion is \(19- 1\).

$$19 - 1=18$$

Answer:

C. 18