Please answer 11-13. say if i'm right for 10 if you can.

Hydrogen and helium are both members of?

Two models of the same compound are shown. in what way is model b better than model a? model b shows the types of elements in the compound, but model a does not. model b shows the three-dimensional shape of the molecule, but model a does not. model b shows how the atoms in the molecule are connected, but model a does not. model b shows the number of atoms of each element in the molecule, but model a does not

Ascientist plants two rows of corn for experimentation.she put fertilizer on row 1 but does not put fertilizer on row 2 both rows receive the same amount of water and light intensity she checks the growth of the corn over 5 months what is the constant in this experiment