Answer:
1/12 of the mass of a ¹²C atom is exactly 1u. Therefore, the mass of the hydrogen atom is greater than 1/12 of the mass of a ¹²C atom.
Explanation:
The unified atomic mass unit is defined as 1/12 of the mass of a ¹²C atom:
1u = 1/12 m ¹²C
Also, the unified atomic mass unit is equal to the mass (in grams) of one mole of a substance, so knowing that 1 mol is equal to 6.022x10²³ atoms, the unified atomic mass unit measured in grams is:
[tex] 1u = \frac{1g}{mol} \cdot \frac{1mol}{6.022 \cdot 10^{23} atoms} = 1.66 \cdot 10^{-24} g = 1.66 \cdot 10^{-27} kg [/tex]
Starting from this definition, we can calculate the mass of ¹H atom respect to the mass of a ¹²C atom:
[tex] m ^{1}H = 1.007825u \cdot \frac{1/12 m ^{12}C}{1u} \cdot \frac{1.66\cdot 10^{-27}kg}{1/12 m ^{12}C} = 1.67 \cdot 10^{-27} kg [/tex]
Therefore, the mass of a ¹H atom is greater than 1/12 the mass of a ¹²C atom.
I hope it helps you!
