Answer:
0.45 moles
Step-by-step explanation:
No. of moles = mass / mass of 1 mole
Mass = 9g
Relative atomic mass of neon = 20
20 is the mass of 1 mole of neon so the number of moles in 9g of neon is...
= 9 ÷ 20
= 0.45 moles
∴ 0.45 moles are present in 9g of neon.