Answer:
Mass = 3.6 g
Explanation:
Given data:
Number of atoms of scandium = 4.77×10²² atoms
Mass of arsenic = ?
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.
one mole = 6.02×10²³ atoms
one mole × 4.77×10²² atoms / 6.02×10²³ atoms
0.08 mol
Mass of scandium
Mass = number of moles × molar mass
Mass = 0.08 mol × 45 g/mol
Mass = 3.6 g
Easy it’s 86 so the third option
Answer:
an electron in the outer energy level of an atom
