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

Responses

58
58

39
39

20
20

19

1 answer

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, the atomic mass is approximately 39 and the atomic number is 19.

So, the calculation would be:

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

Therefore, potassium has 20 neutrons. The correct response is:

20