Answer:
They have completely filled outermost shell
Explanation:
The noble gases are the rarest and occur in trace amounts in the atmosphere because they have completely filled outermost and this makes them unreactive with other elements.
Elements become abundant as they combine with other species to form compounds.
Noble gases on the other hand have a high level of stability and do not readily combine with other species.
Some of these gases are :
Helium
Neon
Argon
Krypton
Xenon
Radon
They have very high ionization energy and very low electron affinity and so will not readily react.
Answer:
Stars several times more massive then the sun have a simpler, quicker, and more spectacular evolutionary sequence. Because super giants are so massive, the core temperature gets much hotter than in giants, so supergiants can fuse elements heavier than hydrogen and helium.
Hydrogen i think. the orbital of hydrogen is peculiar
Answer:
Water has 18 grams per mole so 9 grams is 0.5 moles of water. There are 6.022* 10^23 molecules in a mole. Each water molecule contains one oxygen and two hydrogens.
