To determine the correct composition of water, let's break down the structure of the water molecule.
1. Water's chemical formula is H₂O, which indicates it consists of hydrogen and oxygen atoms.
2. Specifically, the subscript "2" next to the hydrogen (H) signifies there are 2 hydrogen atoms.
3. The absence of a subscript next to the oxygen (O) implies there is only 1 oxygen atom.
Now, let's examine each option:
1. 1 nitrogen and 1 oxygen: This option suggests a molecule with 1 nitrogen (N) and 1 oxygen (O) atom. This does not match the composition of water.
2. 1 oxygen and 2 helium: This option proposes 1 oxygen (O) atom and 2 helium (He) atoms. This is not the correct composition of water, as helium (He) is not involved.
3. 1 oxygen and 2 hydrogen: This option correctly mentions 1 oxygen (O) atom and 2 hydrogen (H) atoms. This matches the H₂O composition of water.
4. 2 oxygen and 1 hydrogen: This option suggests 2 oxygen (O) atoms and 1 hydrogen (H) atom, which would represent a different molecule (potentially hydrogen peroxide, H₂O₂), not water.
Based on the analysis, the correct composition of water is:
- 1 oxygen and 2 hydrogen
Thus, the correct answer is the third option: 1 oxygen and 2 hydrogen.
