Answer:
Mass = 0.084 g
Explanation:
Given data:
Mass of silicon = ?
Number of atoms of silicon = 1.8 × 10²¹ atom
Solution:
Avogadro number:
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.
1 mole = 6.022 × 10²³ atoms
1.8 × 10²¹ atom × 1 mole / 6.022 × 10²³ atoms
0.299× 10⁻² mol
0.00299 mol
Mass of silicon:
Mass = number of moles × molar mass
Mass = 0.00299 mol × 28.1 g/mol
Mass = 0.084 g
