Answer:
A: Helium or Hydrogen
Explanation:
Terrestrial planets are the 4 inner most planets of the solar system which are mercury, venus, earth, Mars, while the giant planets are the 4 outer most which are Jupiter, Saturn, Uranus and Neptune.
Now, these outer most ones are the surface ones and are surrounded primarily by layers of hydrogen and helium gases.
Answer:
Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons
The other dude is rude wrong
The correct answer is Dmitri Mendeleev
Umm its not a i think... lemme see lol
