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

Question

Responses

19
19

39
39

20
20

58

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:

• Atomic number = 19
• Atomic mass ≈ 39

Now, substituting these values into the formula gives:

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

Therefore, potassium has 20 neutrons.