CHEM 107

Matter

Anything that takes up space (volume) and has weight (mass).

Pure substance

Made up of only one type of substance with one chemical formula or symbol.

Element

The simplest type of matter, made up of only one type of atom.

Atom

The smallest unit of matter that retains unique characteristics.

Compound

A pure substance made of two or more elements chemically joined together.

Mixture

A combination of two or more substances that can be separated into its components.

Homogeneous mixture

A mixture with a uniform composition throughout; "homo" means "same."

Heterogeneous mixture

A mixture with a non-uniform composition that varies throughout.

Periodic table

A listing of all elements on Earth, with each block representing a different element.

Chemical symbol

A letter or two derived from the name of an element, often from Latin.

Group

A vertical column of elements with similar chemical behaviors, designated by numbers and letters.

Period

A horizontal row in the periodic table, numbered from 1 to 7.

Metals

Elements that tend to give up electrons.

Macronutrients

Elements needed in quantities greater than 100 mg per day, such as sodium and potassium.

Micronutrients

Elements needed in quantities less than 100 mg per day, such as iodine and iron.

Chemical formula

A representation showing the composition of a compound, indicating the number of atoms of each element.

Physical change

A change in the form of matter without altering its identity.

Chemical change

A change that alters the chemical identity of a substance, known as a chemical reaction.

Reactants

Substances that undergo a chemical reaction.

Products

Substances formed as a result of a chemical reaction.

Law of conservation of mass

The principle that the number of atoms must be the same on both sides of a chemical equation.

Systeme international d’Unites (SI)

The modern version of the metric system.

Significant figures

Digits in a number that represent data known with certainty plus one uncertain digit.

Dimensional analysis

A method for converting units to equivalent units.

Scientific notation

A way to express numbers as a coefficient multiplied by a power of ten.

Density

The comparison of a substance's mass to its volume, calculated as mass/volume.

Specific gravity

The ratio of the density of a sample to the density of water.

Temperature

A measure of hotness or coldness, commonly measured in Celsius or Fahrenheit.

Energy

The capacity to do work or supply heat, existing in potential and kinetic forms.

Specific heat capacity

The amount of heat needed to raise the temperature of 1 g of a substance by 1 °C.

State of matter

The physical form in which matter exists, including solid, liquid, and gas.

Accuracy

The degree of agreement between the true value and the measured value.

Precision

A measure of the agreement of replicate measurements.

Error

The difference between the true value and an estimation, which can be random or systematic.

Dosage calculation

A process involving determining units, given information, conversion factors, and setting up an equation to find the final answer.