CHEM 101 Unit 1 - Atomic Structure (Terms)

Matter

Anything with mass and volume

Pure Substance

Material with constant composition properties, made up of only one substance

Element

A pure substance composed of only one type of atom

Compound

A pure substance composed of whole number ratios of two or more types of atoms

Billiard Ball Atomic Model

The atomic model stating that atoms are the smallest, indivisible component of matter that makes up all material

Plum Pudding Atomic Model

The atomic model stating that electrons are randomly dispersed throughout positive matter because there must be positive charge to offset the negative charge of the electrons (neutral atom)

Nuclear Atomic Model

The atomic model stating that there is a positively charged nucleus in the middle of the atom and that electrons reside in otherwise empty space

Isotope

Atoms of the same element (same number of protons) but different number of neutrons

Ion

An atom or group of atoms that carries a net positive or negative charged, formed due to an element’s electron affinity

Ionic Compound

Compounds made up of a metal and nonmetal monatomic ion or two or more polyatomic ions

Binary Compound

A type of covalent compound made up of two nonmetals

Acid

A type of covalent compound made up of at least one hydrogen atom that produces hydronium ions when in water

Binary Acid

An acid that does not contain oxygen (composed of only H and a nonmetal/polyatomic ion)

Oxyacid

An acid containing oxygen (composed of H and oxoanion)

Oxoanion

Polyatomic ion with general formula XO_n^-

Wavelength

The distance between two consecutive waves/troughs (distance travelled during one full cycle)

Frequency

Number of complete cycles that pass a given point per second

Speed

The distance propagated by a wave per unit of time (c = 3 ×10⁸)

Quantum

The smallest amount of energy (discrete packet) that can be absorbed or emitted in the form of electromagnetic radiation

Photoelectric Effect

A phenomenon in which metal surfaces exposed to monochromatic light cause electrons to be ejected

Emission Spectrum

When a sample of gaseous atoms that absorbs light and releases some of it back in the form of light, forming a discontinuous spectrum with only a few bright lines

Bohr Model for One-Electron Species

An atomic model only applicable to one-electron species stating that electrons can only exist in specific orbits with quantized energy levels, and do not emit or absorb any radiation when in these levels

One Electron Species

Atoms with ionized electrons such that only one electron remains on the atom

Fractional Abundance

the fractional amount of a specific isotope that makes up a percentage of the total atomic mass

Heisenburg’s Uncertainty Principle

The principle stating that it is impossible to know simultaneously the position and momentum of a particle because the more accurately we measure the momentum of a particle, the less accurate its position will be

Wave Function

The probability density of an electron particle being present in a specific location

Principle Quantum Number

Quantum number that defines the size, location, and energy of the orbital

Angular Momentum Number

Quantum number that describes the shape (type) of the orbital

Magnetic Quantum Number

Quantum number that refers to the 3-D orientation of the orbital in the space surrounding the nucleus

Electron Spin Quantum Number

Quantum number that describes the orientation of the electron occupying the orbital