The correct answer is:
c. 1 mole Ne = 20.180 grams = 6.022 x 10^23 atoms
The atomic mass of neon (Ne) is given as 20.180 amu, which means that one mole of neon atoms has a mass of 20.180 grams. This is known as the molar mass of neon.
Avogadro's number, 6.022 x 10^23, represents the number of atoms or molecules in one mole of a substance. Therefore, one mole of neon atoms contains 6.022 x 10^23 atoms.
Option (a) is incorrect because it gives the number of atoms as 1.215 x 10^25, which is more than 2 times Avogadro's number and is not a possible value.
Option (b) is incorrect because it gives the molar mass of neon as 20.180 moles, which is not a valid unit for molar mass.
Option (d) is incorrect because it combines the incorrect values from options (a) and (b).