Hydrogen does not occur in free state on the earth. why?

ExplanatioHydrogen cannot exist in free state as hydrogen needs an electron to attain stability. If an element does not attain stability it cannot exist on its own. In Sun there are large number hydrogen atoms and helium atoms present this creates a lot of energy and nuclear fusions are occured. Gases that attain stability can normally exist on their own. E.g. Argon, Neon, Helium, Krypton and Xenon. Gases that cannot exist on their own are:

H2

O2

N2

Hope it helped a little

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6