Question

explain why the compound you chose has more oxygen atoms.
na₂co₃ has three oxygen atoms in its formula, which is more than co₂ (2), h₂o (1), or ch₄ (0).
co₂ has more oxygen because the “2” in the formula means there are two molecules of oxygen.
h₂o has more oxygen because it has hydrogen too, and when you add them together, it’s more.
na₂co₃ has only one oxygen because there’s no number written after the last o.

Explanation:

In chemical formulas, the sub - script number after an element symbol indicates the number of atoms of that element in one formula unit. In $Na_2CO_3$, the sub - script 3 after O means there are three oxygen atoms. In $CO_2$, there are two oxygen atoms, in $H_2O$ there is one oxygen atom, and in $CH_4$ there are no oxygen atoms. The statement about $CO_2$ misinterprets the sub - script as representing molecules of oxygen instead of atoms. The statement about $H_2O$ wrongly assumes adding hydrogen to oxygen counts towards oxygen quantity. The statement about $Na_2CO_3$ ignores the sub - script 3 for oxygen.

Answer:

A. $Na_2CO_3$ has three oxygen atoms in its formula, which is more than $CO_2$ (2), $H_2O$ (1), or $CH_4$ (0).