Answer is B) - neutrons.
Both protons and neutrons contribute to the mass of an atom. But ₈¹⁷O atom has atomic number as 8. Hence, number of protons is 8. Atomic mass of the given atom is 17.
Atomic mass = number of protons + number of neutrons
Hence, number of neutrons in the given atom is 17 - 8 = 9.
So, the number of neutrons is greater than the number of protons. Hence the greatest composition of ₈¹⁷O atom is neutrons by mass.
