Potassium's atomic number is 19, and its atomic mass is

Question

approximately 39. How many neutrons does potassium
have? (1 point)
19
39
58
20

Answer 1

To determine 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 Mass ≈ 39
• Atomic Number = 19

Now, substitute the values into the formula:

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

Therefore, potassium has 20 neutrons.