Which of the following elements has the fewest valence electrons?
beryllium
boron
carbon
lithium
the answer is lithium but someone had the same question and someone answered wrong. lithium only has on valence electron while beryllium has 2, boron has 3 and carbon has 4 making lithium the correct answer

Answer is: lithium has the fewest valence electrons.

1) Electron configuration of lithium: ₃Li: 1s² 2s¹, it has one valence electron in 2s orbital.

2) Electron configuration of beryllium: ₄Be: 1s² 2s², it has two valence electrons in 2s orbital.

3) Electron configuration of boron: ₅B: 1s² 2s² 2p¹, it has three valence electrons in 2s and 2p orbitals.

4) Electron configuration of carbon: ₄C: 1s² 2s² 2p², it has four valence electrons in 2s and 2p orbitals.