Question

Water is made of two hydrogen atoms and one oxygen atom bonded together. Julia is describing how water undergoes a physical change when it boils. She says that the particles shift to be farther apart and that the oxygen and hydrogen separate. She also says that the total mass of the steam is the same as the initial water, and that heat energy was required to cause the change. She finishes her description by saying that the steam can be turned back into water if it is cooled. Which is the mistake in her description?

Answer 1

That is way too complicated...
I think it is where she says,
"that the particles shift to be farther apart and that the oxygen and hydrogen separate"
The true answer is, I think, that the particles shift to be closer apart, and connect together.

Answer 2

" that the particles shift to be farther apart and that the oxygen and hydrogen separate "

Step-by-step explanation:

The only mistake that Julia made in her description is that the water particles will get separated into hydrogen and oxygen atom. This is not possible during boiling because the heat energy that we are supplying to water to boil is not equal to the bond dissociation energy of the water molecule. The bond dissociation energy of water is very large and is not achieved at 100 degree celcius when water boils.