Question

Given that mH = 1.007825 u, is the mass of a hydrogen atom 1H greater than, less than, or equal to 1/12 the mass of a 12C atom? Select the correct answer and explanation. Given that = 1.007825 , is the mass of a hydrogen atom greater than, less than, or equal to 1/12 the mass of a atom? Select the correct answer and explanation. 1/12 of the mass of a 12C atom is greater than 1 u. Therefore, the mass of the hydrogen atom is greater than 1/12 of the mass of a 12C atom. 1/12 of the mass of a 12C atom is less than 1 u. Therefore, the mass of the hydrogen atom is less than 1/12 of the mass of a 12C atom. 1/12 of the mass of a 12C atom is exactly 1 u. Therefore, the mass of the hydrogen atom is less than 1/12 of the mass of a 12C atom. 1/12 of the mass of a 12C atom is exactly 1 u. Therefore, the mass of the hydrogen atom is greater than 1/12 of the mass of a 12C atom. 1/12 of the mass of a 12C atom is exactly 1 u. Therefore, the mass of the hydrogen atom is equal to 1/12 of the mass of a 12C atom.

Answer 1

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:

$1u = \frac{1g}{mol} \cdot \frac{1mol}{6.022 \cdot 10^{23} atoms} = 1.66 \cdot 10^{-24} g = 1.66 \cdot 10^{-27} kg$      

Starting from this definition, we can calculate the mass of ¹H atom respect to the mass of a ¹²C atom:        

$m ^{1}H = 1.007825u \cdot \frac{1/12 m ^{12}C}{1u} \cdot \frac{1.66\cdot 10^{-27}kg}{1/12 m ^{12}C} = 1.67 \cdot 10^{-27} kg$      

Therefore, the mass of a ¹H atom is greater than 1/12 the mass of a ¹²C atom.

I hope it helps you!