How can you remember the difference between physical and chemical? What are the properties of both of them?
When we talk about physical and chemical, we can describe two different things: physical/chemical changes and physical/chemical properties.
Physical and Chemical Changes
- Physical Changes: When a physical change occurs, the particles of matter rearrange, but don't change into different types of particles. For example, when liquid water turns to steam, the water particles become more separated from one another. Their spatial relationship to one another changes, but they are still water particles. Examples of physical changes include: evaporating, melting, tearing, mixing (but not reacting).
- Chemical Changes: When a chemical change occurs, the particles of matter change into different types of particles. For example, when hydrogen particles react with oxygen particles, water particles are formed. The water particles are completely different particles than either the hydrogen particles or the oxygen particles. Examples of chemical changes include: burning, reacting, decomposing.
Physical and Chemical Properties
- Physical Properties: Physical properties are things that can be observed about a substance without changing the substance into a different substance. For example, if we measure the mass of a substance, when we are finished, the substance will still be the same substance. Examples of physical properties include: mass, volume, density, color, texture.
- Chemical Properties: Chemical properties are things that cannot be observed without changing the substance into another substance. For example, if we want to observed the flammability of magnesium, we have to actually burn it. Once we have observed the magnessium burning, it is no longer magnesium - now it is magnesium oxide. Examples of chemical properties include: flammability, digesting, reacting.
You can remember the difference between physical and chemical by remembering that anything chemical involves a change into a different substance.