Question

potassium’s atomic number is 19, and its atomic mass is approximately 39. how many neutrons does potassium have? (1 point) options: 58, 20, 19, 39

Explanation:

Step1: Recall the formula for neutrons

The number of neutrons in an atom is calculated by the formula: $ \text{Number of neutrons} = \text{Atomic mass} - \text{Atomic number} $

Step2: Identify given values

Atomic number of potassium ($Z$) = 19, Atomic mass of potassium ($A$) = 39 (approximate)

Step3: Calculate the number of neutrons

Substitute the values into the formula: $ \text{Number of neutrons} = 39 - 19 = 20 $

Answer:

20