<P> Period 2 elements involve the 2s and 2p orbitals . They include the biologically most essential elements besides hydrogen : carbon , nitrogen , and oxygen . </P>
<P> Period 2 elements involve the 2s and 2p orbitals . They include the biologically most essential elements besides hydrogen : carbon , nitrogen , and oxygen . </P>
the elements c n and o are contained in
the elements c n and o are contained in
Period 2
Period 2