Science: Pure Substances and Mixtures

Compound

-a compound is made up of 2 or more different kinds of atoms chemically combined. -compounds are pure substances. -1 of the 3 classes of matter. -compounds have different properties from the elements that make them up. -classified by pH/inorganic or organic/role in the body.

Heterogeneous

-a heterogeneous mixture is one that does not have a uniform composition. -suspensions and colloids are a type of heterogeneous mixture.

Homogeneous

-a homogeneous mixture is one when the substances are evenly spread throughout. (uniform composition) -solutions are a type of homogeneous mixture.

Mixture

-a mixture contains a variety of elements and compounds that are not chemically combined with each other. -not a pure substance. -1 of the 3 classes of matter. -can be separated by physical means.

Pure Substance

-a pure substance is a substance that has definite physical and chemical properties. (appearance, melting point, reactivity, etc.) -cannot be formed or broken down by physical changes. -either an element or a compound. -made up of 1 type of particle.

Atom

-atoms are the smallest unit of en element that retains the properties of that element. -all elements, compounds, and mixtures are made up of atoms. -atoms are the basic building blocks of matter.

Element

-elements are made up of one or more of the same kind of atom chemically combined. -elements are pure substances. -1 of the 3 classes of matter. -classified as metals, nonmetals, and metalloids.

Colloid

-in a colloid, the particles are spread throughout a liquid or gas. -look homogeneous but are heterogeneous mixtures. -colloids are a third type of mixture that falls somewhere between suspensions and solutions.

Solution

-in a solution, one substance is dissolved in another substance. -solutions are homogeneous mixtures. -air is an example of a homogeneous mixture.

Suspension

-in a suspension, mixtures in which the particle of a material are spread throughput a liquid or gas but are too large to stay mixed without being stirred or shaken. -a suspensions is a heterogeneous mixture.