Potassium’s atomic number is 19, and its atomic mass is approximately 39. How many neutrons does potassium have?(1 point)
Responses
58
20
19
39
To find the number of neutrons, subtract the atomic number from the atomic mass of an element. In this case, the atomic number of potassium is 19 and the atomic mass is approximately 39. Therefore, the number of neutrons in potassium is approximately 39 - 19 = 20.
So, the correct answer is 20.
To find the number of neutrons in an atom, you can subtract the atomic number from the atomic mass. For potassium:
Atomic number = 19
Atomic mass = 39
Number of neutrons = Atomic mass - Atomic number
Number of neutrons = 39 - 19
Number of neutrons = 20
Therefore, potassium has 20 neutrons.