how many grams of neon will have the same numbere of atoms as 4gms of ca

Molar mass of Ne = 20g
Mass of 1 atom of Ne = Molar mass/Avagadro No = 20 / 6.022*10²³ g
Molar mass of Ca = 40 g
Number of particles in 4 g of Ca = 4/40*6.022*10²³ = 6.022*10²² atoms
Therefore, number of atoms of Ne same as 4 g of Ca = 20*6.022*10²²/6.022*10²³
=20/10
=2 g
Ans: 2g of Ne has the same no of atoms as 4g of Ca.

atomic mass of Ne = 20 u or 20 g ….(Case 1)
moles = given Weight of substance/ Mass of the substance(molecular or atomic)
atomic mass of Ca = 40 u or 40g......(Case 2)
weight of each element given,
weight of Ne = x g
weight of Ca = 4g (from the question)
Using  the mole concept,
no of moles of Ne= no of moles of Ca
(using the mole formula)
x/20  =  4/40
from this x’s  values comes as 2g. Therefore weight of Ne = 2g.