<span>The student is incorrect because helium has 2 valence electrons and it's in group 18 because the first energy level is full. Although helium is placed in Group 18 which generally has 8 valence electrons, it does not have 8 valence electrons as the student suggested. It was grouped together with the noble gases because it exhibits similar properties with them. </span>
This has been an ongoing debate between scientists and astrologers. It is actually classified as a dwarf planet.
Hope this helps!
~Brooke
Answer:
A. 30
Explanation:
Retinol is the chemical form of Vitamin A. It has a chemical formula of C20H30O.
It is processed when retinyl palmitate is broken down in the small intestine. Retinol helps in the proper regulation of eye cells hence a vital component in ensuring good eye sight.
It also helps in the neutralization of free radicals in the body and acts as an antioxidant which prevents cells of the body from ageing.
Answer: Lithium (Li) 16.373%
Chlorine (Cl) 83.627%
Explanation:
It obtains a neutral pH (7). The combination of a strong acid and a strong base results in a neutral pH. The pH of HCl is about 1, and the pH of NaOH is 14.