P, Q, R and S are four organic compounds. P is an unsaturated hydrocarbon.
Q burns but otherwise is unreactive.
R contains a C–C single bond and a C=C double bond.
S undergoes addition polymerization.
Which compounds are alkenes?
A. P and R only B. P, R and S C. P, Q and S D. Q, R and S

In 2002, the rare earth elements mine in mountain pass, california was closed because

If a solution had a ph of 7 what is the solution

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?