Answer:
Gas is for example oxygen or the air we breath and liquid is water.
Explanation:
Answer:
He
Explanation:
A molecule is the smallest physical unit of a substance that can exist independently, consisting of 2 or more atoms chemically combined
He is one atom of Helium
Answer:
Mass = 0.43 g
Explanation:
Given data:
Mass in gram = ?
Number of molecules of NiO = 3.45×10²¹
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.
1 mole = 6.022 × 10²³ molecules
3.45×10²¹ molecules × 1 mol / 6.022 × 10²³ molecules
0.57×10⁻² mol
0.0057 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 0.0057 mol × 74.69 g/mol
Mass = 0.43 g
