Answer:
2.894 x 10²⁴ atoms Ne
Explanation:
To find the amount of neon atoms, you need to (1) convert grams to moles (using the atomic mass) and then (2) convert moles to atoms (using Avogadro's Number). It is important to arrange the ratios/conversions in a way that allows for the cancellation of units (the desired unit should be in the numerator of the ratios in this case). The final answer should have 4 sig figs like the given value (100.0 = 4 sig figs).
Atomic Mass (Ne): 20.180 g/mol
Avogadro's Number:
6.022 x 10²³ atoms = 1 mole
100.0 g Ne 1 mole 6.022 x 10²³ atoms
-------------------- x ----------------- x ------------------------------- = 2.894 x 10²⁴ atoms
20.180 g 1 mole
