How do you classify the difference between a physical and chemical change?

Answer 1

Physical changes occur when objects or substances undergo a change that does not change their chemical composition. A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.

Answer 2

A physical change is one where the substance has changed in appearance, but not in chemical structure. Physical changes can occur when heat energy is added to or taken away from a substance.

For example, I can melt ice for it to become water, chemical formula H2O. It is still the same substance, as no new atoms have been created, and no atoms have been permanently destroyed. In the same way, the H2O has only gained heat energy. It looks different in the sense it is now a liquid rather than a solid, but the actual substance is identical to when it started.

In the same way, I can freeze water (extract heat energy) to change the state of the H2O. Its still the same change, except we have gone the other way, to solid from liquid.

Answer 3

When the physical properties of a material are changed due to the application of a force.

Example: Colloidal silver particles suspended in a photosensitive material precipitate when subjected to light.

Example: Radioactive decay.

Answer 4

A physical chang is a change that can be reversed.

For eg. When you boil water mixed with salt. you get steam out the top and salt in the bottom. so mixing salt in water is a physical change be cause it can be reversed

Answer 5

In chemical change there is a complete conversion of the material from one to another and the property of the original material is changed completely.

And physical change means a mere change in property which can be reconverted in to the original form of material.

I need a more simply answer, I am in 7th grade. Sorry. :(

Answer 6

When a substance changed state, eg - from a solid to a liquid, or from a liquid to a gas. A physical change can be reversed, as in you can reverse the reaction. Eg. water can be frozen to make ice.