Question

To fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add ... to fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add ... 2 electrons. 3 electrons. 8 electrons. 1 electron. can't tell without knowing which element it is.

Answer 1

To fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add 2 electrons.
₈O 1s²2s²2p⁴.
₁₀Ne 1s²2s²2p⁶.
Neon is noble gas and has eight electrons in valence shell and oxygen has six electrons in valence shell and gain two electrons.