Answer:
88 g
Explanation:
Given data:
Number of atoms of helium = 1.3×10²⁵
Mass in gram = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For helium:
1 mol = 6.022 × 10²³ atoms of He
1.3×10²⁵ atoms of He × 1mol / 6.022 × 10²³ atoms of He
0.22×10² mol
22 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 22 mol × 4 g/mol
Mass = 88 g
