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

Question

Responses

20
20

58
58

19
19

39

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

Now, substituting these values into the formula:

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

Thus, potassium has 20 neutrons.

The correct response is 20.