Question

which two elements have the same number of energy levels with electrons in them? (1 point)
○ krypton and neon
○ neon and sodium
○ lithium and francium
○ boron and oxygen

Explanation:

Elements in the same period of the periodic - table have the same number of electron energy levels. Lithium (Li) is in period 2 and francium (Fr) is in period 7. Neon (Ne) is in period 2 and sodium (Na) is in period 3. Krypton (Kr) is in period 4 and neon (Ne) is in period 2. Boron (B) and oxygen (O) are both in period 2, so they have the same number of energy levels with electrons.

Answer:

Boron and oxygen