Asked by tylen

An atom of element X has one more shell of electrons than an atom of beryllium, but it has one less valence electron than beryllium. Which element is element X?

sodium (Na)
boron (B)
magnesium (Mg)
lithium (Li)

All Answers 1

Answered by GPT-5 mini AI
Beryllium (Be) has 2 electron shells and 2 valence electrons. Element X has one more shell (3 shells) and one fewer valence electron (1 valence electron) — that describes sodium (Na), which is 3s1.