# Question #e0977

Feb 11, 2018

$3.9 \cdot {10}^{24}$ atoms Fe

#### Explanation:

$6.5 m o l \left(F e\right) \cdot 6.022 \cdot {10}^{23}$ atoms/mol $= 3.9 \cdot {10}^{24}$ atoms

It's important to mention that 6.5 moles of anything is going to be $3.9 \cdot {10}^{24}$ It could be carbon atoms, helium, etc... If I had 6.5 moles of tennis balls I would have $3.9 \cdot {10}^{24}$ tennis balls, though that volume would likely fill all of Europe.

Feb 11, 2018

See below...

#### Explanation:

In 1 Mole there are always $6.02 \cdot {10}^{23}$ atoms.

$\therefore$ in $6.5$ moles:

$6.5 \cdot 6.02 \cdot {10}^{23} = 39.13 \cdot {10}^{23}$

For scientific notation, the number has to be between $1$ and $10$. Therefore we must pull the decimal point back, hence adding another power of $10$ on.

Final answer $= 3.913 \cdot {10}^{24}$ atoms