I want someone he is good in chemistry

Idon’t understand this page, can someone ?

Which characteristics can be used to differentiate star systems? check all that apply.

Pinene is an unsaturated hydrocarbon found in pine resin. if pinene has m+ = 136 and contains 1 double bond(s) and 2 ring(s); what is its molecular formula? enter the formula in the form ch first, then all other atoms in alphabetical order; do not use subscripts. the formula is case-sensitive