Question

How many atoms are found in 4.20 g of Magnesium?

Answer 1

Answer: The number of atoms found in given amount of magnesium is
`1.042* 10^(23)`

Step-by-step explanation:

To calculate the number of moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}`

Given mass of magnesium = 4.20 g

Molar mass of magnesium = 24.31 g/mol

Putting values in above equation, we get:

`\text{Moles of magnesium}=(4.20g)/(24.31g/mol)=0.173mol`

According to mole concept:

1 mole of an element contains
`6.022* 10^(23)` number of atoms

So, 0.173 moles of an element contains =
`0.173* 6.022* 10^(23)=1.042* 10^(23)` number of atoms

Hence, the number of atoms found in given amount of magnesium is
`1.042* 10^(23)`

Answer 2

There are 1.041×10²³ atoms in 4.20g of Magnesium.

Step-by-step explanation:

To find the amount of atoms in 4.20 g of Magnesium we need de molar mass of Mg: 24.305 g/mol

According to Avogadro number there are 6.022×10²³ particles in 1 mol, so the number of atoms of Mg is:

`4.20 g Mg*(1 molMg)/(24.305gMg) *(6.022*10^(23)atoms )/(1 mol Mg) = 1.041*10^(23)atoms Mg`