Shanae771 Shanae771

05-06-2015
Chemistry

contestada

What is the total number of protons in the nucleus of an atom of potassium-42?
(1) 15 (3) 39
(2) 19 (4) 42

Respuesta :

stephenlee0912 stephenlee0912

05-06-2015

The answer is (2) 19. The number of protons of any isotope of a given element is just its atomic number (because the number of protons identifies the element). Potassium's atomic number is 19.

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