Let's solve the problem step-by-step:
1. Understand the Problem:
We need to find the number of moles of Carbon present in 0.6 milligrams (mg) of Carbon. The atomic mass of Carbon (C) is given as 12.
2. Convert Mass into Grams:
Since the unit of atomic mass is in grams per mole (g/mol), we first convert the given mass from milligrams to grams.
\(\[
\text{mass in grams} = \text{mass in milligrams} \times 10^{-3}
\]\)
\(\[
\text{mass in grams} = 0.6 \ \text{mg} \times 10^{-3} = 0.0006 \ \text{g} = 6 \times 10^{-4} \ \text{g}
\]\)
3. Formula for Number of Moles:
The number of moles (\(\( n \)\)) can be calculated using the formula:
\(\[
n = \frac{\text{mass}}{\text{molar mass}}
\]\)
In this case, the molar mass of Carbon is 12 g/mol.
4. Calculate Number of Moles:
Plugging in the values, we get:
\(\[
n = \frac{6 \times 10^{-4} \ \text{g}}{12 \ \text{g/mol}}
\]\)
\(\[
n = \frac{6 \times 10^{-4}}{12}
\]\)
\(\[
n = 0.5 \times 10^{-4} \ \text{moles}
\]\)
5. Conclusion:
The number of moles present in 0.6 milligrams of Carbon is \(\( 0.5 \times 10^{-4} \)\).
Thus, the correct answer is:
\(\[
\text{a) } 0.5 \times 10^{-4}
\]\)
