How many neutrons are in oxygen-19?

Answer 1

Potassium has several known isotopes, some of which are stable or at least very long lived. 19K is not one of hem. 32K (13 neutrons) to 55K (36 neutrons) have been identified. The stable ones are 39K and 41K. Should an isotope 19K be created, it would have no neutrons. It would decay by electron capture (most likely) to something like fluorine. With a great number of gamma photons emitted as well.

Answer 2

Isotopes of an element differ only in the number of neutrons. Oxygen has atomic number 8, meaning 8 protons. It has Atomic Mass 16, meaning 8 neutrons. In the O-19 isotope, the mass is now 19, meaning 11 neutrons (19 - 8).

Answer 3

You take 19 and subtract 8 (amt. of neutrons in a neutral atom of oxygen) and get 11, so 11 is your answer.

Answer 4

Number of neutrons = Mass number - atomic number = 39 - 19 = 20

Answer 5

10 neutrons