Respuesta :
Answer:
116.67 g of rubidium
Explanation:
Concept tested: Moles of an element and the Avogadro's constant
- An element is made up of similar atoms.
- One mole of an element contains atoms that are equivalent to the Avogadro's number.
- Avogadro's number is 6.022 × 10^23
- Therefore; 1 mole of an element = 6.022 × 10^23 atoms
In this case;
Element is Rubidium
1 mole of Rubidium = 6.022 × 10^23 atoms
Step 1: Number of moles of Rubidium
Moles = Number of atoms ÷ Avogadro's constant
Thus;
Moles of Rubidium = 8.22 × 10^23 atoms ÷ 6.022 × 10^23 atoms
= 1.365 moles
Step 2: Mass of rubidium
Mass = Number of moles × Molar mass
Molar mass of rubidium = 85.47 g/mol
Therefore;
Mass of rubidium = 1.365 moles × 85.47 moles
= 116.67 g
Therefore, the mass of 8.22 × 10^23 atoms of rubidium is 116.67 g