Why is hydrogen not considered part of any group

Hydrogen atoms one outer electron so would be placed in group 1. However all group 1 elements are metals and elements in the same group have similar properties. Hydrogen is a non-metal and does not behave in the same way as the other group 1 elements, so that is why it is on its own.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.

50.23 i believe is correct but don't quote me on that.