Answer:
27 moles of H₂
Explanation:
Equation of reaction:
N₂ + 3H₂ → 2NH₃
From the equation of reaction,
3 moles of H₂ is required to produce 2 moles of NH₃
3 moles H₂ = 2 moles of NH₃
X moles of H₂ = 18 moles of NH₃
X = (3 * 18) / 2
X = 27 moles of H₂
27 moles of H₂ is required to produce 18 moles of NH₃
<u>Answer:</u> The fraction of atom's mass contributed by nucleus is 0.99
<u>Explanation:</u>
Nucleons are defined as the sub-atomic particles which are present in the nucleus of an atom. Nucleons are protons and neutrons.
The isotopic symbol of Helium-4 atom is 
Number of electrons = 2
Number of protons = 2
Number of neutrons = 4 - 2 = 2
We are given:
Mass of He-4 atom = 
Mass of 1 electron = 
Calculating the mass contributed by the nucleus = 
Mass of the nucleus of He-4 atom = 
To calculate the fraction of atom's mass contributed by the nucleus, we use the equation:

Putting values in above equation, we get:

Hence, the fraction of atom's mass contributed by nucleus is 0.99
6.02 times 10 to the 23 power, which is Avogadros number
It it important because it makes people wonder how things work and are made which makes it so they want to move forward with experiments <span />