The quantity equal to one mole is defined using which isotope

a. carbon 12

b. carbon 13

c. nitrogen 14

d. oxygen 16

A.

Explanation:

There are several reasons that Carbon-12 was chosen as the standard for determining the relative mass of other atoms.

Its abundance on earth Carbon-12 is a very stable isotope atom Its has the same number of neutrons and protons hence more ideal to use for a precise calculation of amu (atomic mass unit) -

The mass of an atom are based on the ¹/12 mass of Carbon-12.