how many valence electrons does lithium have

Lithium has one valence electron. This electron is located in the 2s subshell of the second principal energy level, which is its outermost shell. The electron configuration of lithium is 1s22s11s^22s^11s22s1, indicating two electrons in the first shell and one valence electron in the second shell. Because lithium is in Group 1 of the periodic table, it typically has one valence electron, which is loosely held and makes lithium highly reactive