Chemistry: Elements, Compounds, Mixtures, and Solutions Key Concepts

Element

A pure substance made of only one kind of atom; cannot be broken down chemically

Compound

a specific type of molecule containing at least two different elements

Mixture

A physical combination of substances that are not chemically bonded

Solution

A homogeneous mixture where one substance is dissolved in another

Suspension

A heterogeneous mixture with large particles that settle over time

Colloid

A mixture with medium-sized particles that do not settle and scatter light

Alloy

metallic substance composed of two or more elements, as either a compound or a solution

Soluble

the ability to be dissolved in a solvent

Insoluble

Not able to be dissolved in a solvent

Solute

The substance that is dissolved in a solvent

Solvent

The substance that dissolves the solute

Homogeneous

A mixture that is uniform throughout

Heterogeneous

A mixture that is not uniform throughout

Dilute

A solution with a small amount of solute compared to solvent

Concentrated

A solution with a large amount of solute compared to solvent

Saturated

A solution that cannot dissolve any more solute at a given temperature

Unsaturated

A solution that can still dissolve more solute

Supersaturated

A solution containing more dissolved solute than normally possible

Pure Substance

matter with a uniform and definite chemical composition

Physical Change

A change that affects form or state but not chemical identity

Chemical Change

A change that produces one or more new substances

Distillation

A separation method based on differences in boiling points

Filtration

A separation method that removes solid particles from a liquid using a filter

Centrifuge

A device that separates substances by spinning them rapidly

Metal

An element that is shiny, malleable, and conducts heat and electricity

Nonmetal

An element that lacks metallic properties and may be brittle or gaseous

Metalloid

An element with properties of both metals and nonmetals

Atom

The smallest unit of an element that retains its properties

Molecule

any group of two or more atoms chemically bonded

Specific Ratios

Elements in a compound always combine in fixed proportions

Magnetism

A physical property that allows materials to be attracted to a magnet

Filterable

Can be separated using filtration

Non-filterable

Cannot be separated using filtration

Scatters Light

The phenomenon where light waves change direction as they encounter particles that are medium or large. causing them to spread out in different directions, like bouncing off tiny obstacles.

Does Not Scatter Light

A property of true solutions

H2O

Chemical formula for water

CO2

Chemical formula for carbon dioxide

NaCl

Chemical formula for sodium chloride

Chemical Formula

A combination of symbols and numbers showing the composition of a compound

Chemical Symbol

A one- or two-letter abbreviation representing an element