Question

Which of the following is not a correct formula unit? (2 points)
Select one:
a. K2O
b. MgO2
c. Al2O3
d. SrO

Answer 1

Any ideas? Hint: Know what are cations and anions, and know the charges of each metals and nonmetals.

Here is an image that simply tells you the charges of each group.

Answer 2

Here is an example of how to write the formula unit by switching the charges to subscripts.

Answer 3

Hint Mg anion has a charge of +2
O has a acharge od -2