Which change is chemical?(1 point)

Responses

water boiling: solid water becoming gaseous water
water boiling: solid water becoming gaseous water

water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules
water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules

water freezing: liquid water becoming solid water
water freezing: liquid water becoming solid water

water evaporating: liquid water becoming gaseous water

2 answers

The change that is chemical is:

water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules.

This process involves breaking the chemical bonds in water (H2O) to produce two different substances: hydrogen (H2) and oxygen (O2), which is a chemical change. The other processes mentioned are physical changes, where the state of the substance changes but its chemical composition remains the same.

Which number remains unchanged during photosynthesis?(1 point)
Responses

the number of glucose molecules
the number of glucose molecules

the number of water molecules
the number of water molecules

the number of carbon atoms
the number of carbon atoms

the number of carbon dioxide molecules