Choose the statements that are true about hydrogen and oxygen.

a. hydrogen has a total of two electron shells.
b. if one hydrogen atom bonds to one oxygen atom, both atoms have full valence shells.
c. when hydrogen has two electrons in its valence shell, it has a full valence shell.
d. hydrogen can bond with oxygen to make water.

C and D

Explanation:

A. Hydrogen has a total of two electron shells.

It is false because hydrogen has only one electron and maximum electron in first valence shell is two. Therefore,  it has only one electron shell.Hence, option is false.

B.If one hydrogen atom bonds to one oxygen atom , both atoms have full valence shells.

It is false, because hydrogen required one electron for filling  its valence shell but oxygen required two electrons for filling its valence shell . The electrons in a bond are two. Therefore, if one hydrogen atom bond with one oxygen atom then the valence shell of oxygen is incomplete .Hence, option B is false.

C.When hydrogen has two electrons in its valence shell , it has a full valence shell.

It is true because hydrogen has only one shell and it required two electrons for fillings its valence shell.Hence, option C is true.

D.Hydrogen  can bond with oxygen to make water.

Yes , hydrogen can bond with oxygen to make water because the chemical formula of water is .Two hydrogen atom and one oxygen required to make water. Hence. it is true.

C and D

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation: