Question

how many atoms are there in 3 gram of mg​

Answer 1

Magnesium =27u

in 3 grams

No. of Moles =Given Mass/Atomic Mass

therefore No. of Moles =3/27

=1/9 moles

So No. of Atoms = No. of Moles*NA

No. of Atoms=6.022*10^23/9

=2*10^23/3

Hope That Helps

Answer 2

The Number of atoms in 3gm of Magnesium is 0.75 * 10²³.

Given:-

Mass of Magnesium (m) = 3gm

To Find:-

Number of atoms in 3gm of Magnesium.

Solution:-

To find out the Number of atoms we need to follow these simple steps.

As,

Mass of Magnesium (m) = 3gm

Molar Mass of Magnesium (mm) = 24gm

Number of atoms (N) = ?

Before going to the Number of atoms, first we have to find out the Number of moles of Magnesium.

$n \: = \: \frac{ \:given \: mass}{molar \: mass}$

$n \: = \: \frac{m}{mm}$

$n \: = \: \frac{3}{24}$

$n \: = \: \frac{1}{8}$

Now,

No. of moles =

$\frac{no. \: of \: atoms}{avogadro \: number}$

Number of atoms = Number of moles * avogadro number

N = n * Na

N =

$\frac{6.02 \times {10}^{23} }{8}$

N =

$0.75 \times {10}^{23}$

Hence, the Number of atoms in 3gm of Magnesium is 0.75 * 10²³.

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