Summing Up
a. Atoms combine to form molecules in specific ratios. In a water molecule, for example, there are two hydrogens for every one oxygen. If this ratio were different-say two hydrogens to two oxygens would the shape of the molecule also be different?
b. Would you still have a water molecule? Ne, because
The Correct Answer and Explanation is:
Question a:
If the ratio of atoms in a water molecule changed from two hydrogens to one oxygen (H₂O) to two hydrogens to two oxygens (H₂O₂), would the shape of the molecule be different?
Answer:
Yes, the shape of the molecule would be different.
Question b:
Would you still have a water molecule? Why or why not?
Answer:
No, you would not have a water molecule anymore
Water (H₂O) is a molecule composed of two hydrogen atoms covalently bonded to one oxygen atom. The molecular structure and shape of water are fundamental to its unique properties. In a water molecule, the oxygen atom has two lone pairs of electrons and forms bonds with two hydrogen atoms at an angle of approximately 104.5 degrees. This bent or V-shaped geometry is critical for water’s polarity, which allows it to form hydrogen bonds and exhibit characteristics such as high surface tension, solvent capabilities, and a high boiling point.
If the ratio changed to two hydrogens and two oxygens (H₂O₂), you would have a completely different molecule called hydrogen peroxide, not water. Hydrogen peroxide has a different chemical formula, molecular structure, and properties. In H₂O₂, the two oxygen atoms are bonded together (forming an O-O single bond), with each oxygen also bonded to a hydrogen atom. The shape is more complex, with a non-linear, “open book” shape and bond angles that differ from water. This molecular geometry causes hydrogen peroxide to have distinct chemical behavior—it is much less stable and acts as a strong oxidizer and disinfectant, unlike water.
Because chemical properties depend heavily on molecular structure and the types and numbers of atoms involved, changing the ratio alters the fundamental nature of the substance. Therefore, two hydrogens to two oxygens do not constitute water but a different chemical compound with a different shape and function. The name “water” is reserved specifically for H₂O due to its unique molecular structure and properties.
In summary, the ratio of atoms determines both the identity and shape of the molecule. Changing the ratio changes the molecule’s structure, shape, and chemical identity, meaning you would no longer have water but a different molecule altogether.
