Physical Changes and Chemical Changes 2022

physical change

A type of change that involves the physical properties of a substance. No new matter is made.

chemical change

Process by which substances are changed into different substances with different properties

phase change

A physical change that changes the state of matter (solid, liquid, gas, plasma).

molecule

made up of two or more atoms combined chemically

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds / a type of molecule

mass

a measure of the amount of matter present

Atom

the basic unit of a chemical element / contains protons, neutrons and electrons

Mixture

A combination of two or more substances that are not chemically combined

matter

anything that has mass and takes up space

chemical property

a property of matter that describes a substance's ability to participate in chemical reactions

physical property

A characteristic of a pure substance that can be observed without changing it into another substance

Reactivity

the property that describes how readily a substance combines chemically with other substances to make new matter

pure substance

A substance made of only one kind of matter and having definite properties.

Indicators of a chemical change/reaction.

Gasses formed, heat changes, light, or sound production. This occurs as a result of new matter being made (atoms are rearranged and compounds broken)

change in shape, size, weight, density OR phase

types of physical changes

Solubility

the ability of one substance to dissolve in another at a given temperature and pressure

particle

often referencing components of atoms, or other small types of matter that have unique physical an chemical properties / from subatomic particles, such as electrons, to particles large enough to be seen, such as particles of dust floating in sunlight

crystal

a solid in which the atoms are arranged in a pattern that repeats again and again

Flammability

the ability of a substance to burn

units for density

g/mL or g/cm3

In a density column, these substances will be near the top

ones that are less dense

In a density column, these substances will be near the bottom

ones that are more dense

Density

mass/volume

melting point

the temperature at which a given solid will melt. This is a physical property.