Question

multiple choice 10 points
what is the correct formula for the compound, lithium oxide?
lio
lio₂
li₂o
li₂o₂

Explanation:

Step1: Determine the charge of lithium ion

Lithium (\(Li\)) is in Group 1 of the periodic table. So, the lithium ion has a charge of \(Li^+\) (loses 1 electron).

Step2: Determine the charge of oxide ion

Oxygen (\(O\)) in oxide form has a charge of \(O^{2 -}\) (gains 2 electrons).

Step3: Balance the charges

To balance the charges in the compound, we need 2 \(Li^+\) ions for every 1 \(O^{2 -}\) ion. Using the criss - cross method (where we take the magnitude of the charge of one ion as the subscript of the other ion), for \(Li^+\) and \(O^{2 -}\), the formula becomes \(Li_2O\).

Answer:

\(Li_2O\) (the third option)