Stable Ions Quick Check
4 of 54 of 5 Items
Question
Potassium’s atomic number is 19, and its atomic mass is approximately 39. How many neutrons does potassium have?(1 point)
Responses
19
20
58
39
The number of neutrons in an atom can be calculated by subtracting the atomic number (which represents the number of protons) from the atomic mass.
In this case, the atomic number of potassium is given as 19, and the atomic mass is approximately 39.
So, the number of neutrons in potassium can be calculated as:
39 - 19 = 20
Therefore, potassium has 20 neutrons. Thus, the correct answer is 20.
To find the number of neutrons, you need to subtract the atomic number from the atomic mass. In this case, the atomic number of potassium is 19 and the atomic mass is approximately 39. So, to find the number of neutrons in potassium, you subtract 19 from 39.
39 - 19 = 20
Therefore, potassium has 20 neutrons.
The correct answer is 20.