Question

in a 1:1 ratio, which of these pairings would create an octet for each atom?
one aluminum atom and one oxygen atom
one potassium atom and one sulfur atom
one magnesium and one chlorine
one magnesium and one oxygen

Explanation:

Step1: Analyze aluminum - oxygen

Aluminum (Al) has 3 valence electrons and oxygen (O) has 6 valence electrons. In a 1:1 ratio, they won't form an octet for each atom.

Step2: Analyze potassium - sulfur

Potassium (K) has 1 valence electron and sulfur (S) has 6 valence electrons. In a 1:1 ratio, they won't form an octet for each atom.

Step3: Analyze magnesium - chlorine

Magnesium (Mg) has 2 valence electrons and chlorine (Cl) has 7 valence electrons. In a 1:1 ratio, they won't form an octet for each atom.

Step4: Analyze magnesium - oxygen

Magnesium (Mg) has 2 valence electrons and oxygen (O) has 6 valence electrons. Magnesium donates 2 electrons to oxygen. Magnesium then has a stable electron - configuration (a full outer shell from the previous shell), and oxygen gains 2 electrons to complete its octet.

Answer:

one magnesium and one oxygen