Chemistry Terms

Chemistry

The study of the composition, structure and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes

Physical Properties

A characteristic that can be observed or measured without changing the identity of the substance

Chemical Properties

Relates to the ability of a substance to undergo changes that transform it into different substances

Precision

Describes the closeness or reproducibility of a set of measurements

Atom

The smallest unit of an element that maintains the chemical identity of that element; the building block of matter

Neutron

A neutral subatomic particle in the nucleus of every atom except simple hydrogen

Nucleus

Positively charged center of an atom containing protons and neutrons

Anion

An ion with a negative electrical charge

Homogenous

A mixture with uniform composition

Atomic Mass Unit

A unit of measurement used to measure the mass of atoms

Covalent Bond

The mutual sharing of one or more pairs of electrons between two atoms

Octet Rule

A rule stating that atoms lose, gain, or share electrons in order to have a full valence shell of 8 electrons

Mass Number

The sum of protons and neutrons in the nucleus of an atom

Avogadro’s Number

6\.02 x 10^23

Chemical Changes

A change in which one or more substances are converted into different substances; a reaction

Physical Changes

A change in a substance that does not involve a change in the identity of the substance

Mass

A measure of the amount of matter in an object

Accuracy

The closeness of a value to the correct or accepted value of the quantity measured

Proton

A positively charged particle that is in the nucleus of an atom

Electron

A negatively charged particle that travels around the nucleus of an atom

Cation

An ion with a positive electrical charge

Metalloids

Share some properties of metals and some of nonmetals, some shiny and some dull, some malleable and some not, some ductile and some not, semiconductors of electric energy

Heterogenous

A mixture without uniform composition

Ionic Bonding

The outermost electrons of one atom are transferred permanently to another atom

Chemical Bond

The bond that holds atoms together in molecules

Atomic Number

The number determining where an element is arranged; equal to the number of protons

Mole

Equal to Avogadro’s Number