Question

how many protons and neutrons are in an atom of k - 39?
number of protons =
number of neutrons =

Explanation:

Step1: Identify element's atomic number

Potassium (K) has atomic number 19. Atomic number = number of protons. So, number of protons = 19.

Step2: Calculate number of neutrons

Mass - number of K - 39 is 39. Mass number=number of protons + number of neutrons. So, number of neutrons = 39 - 19 = 20.

Answer:

Number of protons = 19
Number of neutrons = 20