Question

question 4 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 atomic - electron relationship

In a neutral atom, the number of electrons equals the atomic number. Potassium has an atomic number of 19, so a neutral potassium atom has 19 electrons.

Step2: Consider electron - loss for ion - formation

When potassium forms an ion by losing 1 electron, we subtract 1 from the number of electrons in the neutral atom. So, \(19 - 1=18\).

Answer:

C. 18