This is funny, because last year I did a project on wave lengths, but despite that; Violet light has more energy than yellow light because on the light spectrum, violet has the least wavelengths. This means they carry the most energy.
The atomic number is also the number of protons in the nucleus of an atom of a specific element, in this case Xenon. Xenon is represented on the periodic table as Xe. Find that and look at the number in the top center of the square for Xenon. In this case, the atomic number is 54.
Answer:
\large \boxed{\text{12.3 mol HCl}}
Explanation:
We need a balanced chemical equation with moles.
2HCl +Ca(OH)₂ ⟶ CaCl₂ + 2H₂O
n/mol: 12.3
The molar ratio is 2 mol H₂O:2 mol HCl.

214.0560
+ 9.3456
=223.4016