Question

How many protons are in the nucleus of a potassium atom with a mass number of 39?

image

Select {responseValue}
39

Select {responseValue}
19

Select {responseValue}
20

Select {responseValue}
58

Answers

GPT-4o mini
The number of protons in an atom is determined by its atomic number. For potassium (K), the atomic number is 19, which means there are 19 protons in the nucleus of a potassium atom, regardless of its mass number.

Thus, the correct answer is **19**.