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dsp73
3 years ago
11

How many helium atoms are in a 12.0 g sample?

Chemistry
2 answers:
lakkis [162]3 years ago
8 0
The correct answer is 2.99 helium atoms.


I hoped this helped!
MaRussiya [10]3 years ago
6 0

<u>Answer:</u> The number of helium atoms present are 18.066\times 10^{23}

<u>Explanation:</u>

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

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

Given mass of helium = 12.0 g

Molar mass of helium = 4 g/mol

Putting values in above equation, we get:

\text{Moles of helium}=\frac{12.0g}{4g/mol}=3mol

According to mole concept:

1 mole of an element contains 6.022\time 10^{23}  number of atoms.

So, 3 moles of helium will contain = 3\times 6.022\times 10^{23}=18.066\times 10^{23} number of atoms.

Hence, the number of helium atoms present are 18.066\times 10^{23}

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