Question

Potassium’s atomic number is 19, and its atomic mass is approximately 39. How many neutrons does potassium have?(1 point)
Responses

20
20

19
19

58
58

39

Answer 1

To find the number of neutrons, subtract the atomic number from the atomic mass.

Atomic mass: 39
Atomic number: 19

Number of neutrons = Atomic mass - Atomic number
Number of neutrons = 39 - 19
Number of neutrons = 20

Therefore, potassium has 20 neutrons.