How Many Atom Of Oxygen Are In 2h20?

There are 2 atoms of oxygen.
O.o"
i'm slightly confused at why avogodro's number is used if it is just atoms.

Since there are two molecules in
2(H2O)
note the first 2.
Then, every thing inside the bracket is multiplied by 2, as there are two molecules, and H2O is only one molecule.
In one water molecule, or H2O, there is only one atom of oxygen.
THEREFORE, there are 2 oxygen atoms..
And there are four hydrogen atoms. Oo

First I would recommend expressing your compound in the correct notation and no. Of moles, and correctly written your compound might be written as follows:

2H₂O, in which case you have 2 molars of Oxygen, which means you use the following calculations to know the number of Oxygen atoms in the preceding expression:

2 x 6.023X10²³=1.024x10²⁴ Oxygen atoms contained in 2H₂O<sub>.

*^{Avogodro's number=6.023x10</sub>23}