which is an example of physical change
1.water decomposing into hydrogen and oxygen
2.potassium and bromine combining to form potassium bromide
3.solid ice melting into liquid water
4.none of the above
i think its 3.
A physical change in a substance doesn't change what the substance is.
I also think it is 3.
It couldn't be 1 or 2.
3 it is.
You are correct! The correct example of a physical change is option 3: solid ice melting into liquid water. Let me explain why:
A physical change refers to a change in a substance where its physical properties are altered, but its chemical composition remains the same. In this case, when solid ice melts into liquid water, the substance changes from a solid state to a liquid state, but the chemical composition (H2O) remains unchanged. The process of melting is a physical change because it does not involve the breaking or formation of any chemical bonds.
Option 1: Water decomposing into hydrogen and oxygen represents a chemical change, not a physical change. This is because the substances (water, hydrogen, and oxygen) involved are chemically different from each other. The chemical bonds between hydrogen and oxygen are broken, and new bonds are formed to create the separate elements.
Option 2: Potassium and bromine combining to form potassium bromide is also an example of a chemical change. In this case, the chemical composition of the substances changes as the elements potassium and bromine react and form a new compound, potassium bromide.
Therefore, option 3 correctly represents a physical change since it involves a change in state (solid to liquid) while maintaining the same chemical composition.