How many grams are in 4.23 x 1024 atoms of He?

28.11g

Explanation:

Step 1:

Background understanding:

From Avogadro's hypothesis, 1 mole of any substance contains 6.02x10^23 atoms. This also indicates that 1 mole of helium (He) contains 6.02x10^23 atoms.

1 mole of He = 4g

Step 2:

Determination of the mass of He that contain 4.23x10^24 atoms. This is illustrated below:

4g of He contains 6.02x10^23 atoms.

Therefore Xg of He will contain 4.23x10^24 atoms i. e

Xg of He = (4x4.23x10^24) / 6.02x10^23

Xg of He = 28.11g

Therefore, 28.11g of He contains 4.23x10^24 atoms