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 39 39 58 58 19

what is 100% correct

Answer 1

To find the number of neutrons in an atom, you can use the formula:

\[ \text{Number of neutrons} = \text{Atomic mass} - \text{Atomic number} \]

For potassium (K):

- Atomic number = 19
- Atomic mass ≈ 39

So,

\[ \text{Number of neutrons} = 39 - 19 = 20 \]

Therefore, the correct answer is **20**.