a compound of general formula qr contains no hydrogen, q is the alkali metal of lowest atomic mass, and r contains the elements oxygen and carbon in a 3:1 ratio. write the name and the formula of the compound

Li2CO3 - Lithium carbonate

Explanation:

If you look at the periodic table of elements, you will see that, from all alkali metals, Lithium is the one with the lowest atomic mass. So we can conclude that the element q in the compound qr is Lithium.

The task says that in the compound qr, r contains the elements oxygen and carbon in a 3:1 ratio. It means that we have 3 oxygen and 1 carbon atom in this compound, which can be written as CO3.

From the information above, we can conclude the compound that we are looking for is Li2CO3 - Lithium carbonate.