The atomic mass of the element neon (Ne) is 20.180 amu. Which measurement is correct?
a) 1 gram Ne = 20.180 moles = 6.022×10²³ atoms
b) 1 gram Ne = 20.180 moles = 1.215×10²⁵ atoms
c) 1 mole Ne = 20.180 grams = 1.215×10²⁵ atoms
d) 1 mole Ne = 20.180 grams = 6.022×10²³ atoms
Naturally occurring neon contains three isotopes. Therefore, its atomic mass is an average composed of these isotopes.
The correct measurement is:
c) 1 mole Ne = 20.180 grams = 6.022×10²³ atoms
This is because 1 mole of any element contains Avogadro's number (6.022 × 10²³) of atoms, which is the number of atoms that exist in 12 grams of carbon-12. The atomic mass of Ne (20.180 g/mol) indicates that one mole of Ne contains 20.180 grams.