General Chemistry

Atom

The basic unit of matter, everything around you is made of atoms.

Subatomic Particles

The smaller particles that make up an atom: protons, neutrons, and electrons.

Protons

Subatomic particles that carry a positive charge.

Neutrons

Subatomic particles that have no charge.

Electrons

Subatomic particles that carry a negative charge.

Nucleus

The center of the atom, containing protons and neutrons.

Electron Shells

Regions where electrons move around the nucleus of an atom.

Atomic Number

The number of protons in an atom, which also equals the number of electrons in a neutral atom.

Mass Number

The total number of protons and neutrons in an atom.

Element

A pure substance containing only one type of atom.

Isotope

Atoms of the same element that have different numbers of neutrons.

Chemical Compound

A substance formed when two or more different elements chemically combine.

Ionic Bond

A chemical bond formed when electrons are transferred from one atom to another.

Covalent Bond

A chemical bond that occurs when two atoms share electrons.

Polar Covalent Bond

A covalent bond where electrons are shared unequally, leading to slightly charged regions.

Nonpolar Covalent Bond

A covalent bond where electrons are shared equally, with no charged regions.

Van der Waals Forces

Slight attractions between oppositely charged regions of nearby molecules.

Hydrogen Bonds

Weak attractions involving hydrogen and an electronegative atom, typically oxygen or nitrogen.

Octet Rule

Atoms tend to gain, lose, or share electrons to fill their outermost shell with 8 electrons.

Lewis Dot Structure

A representation that shows the valence electrons of an element.

Polar Molecule

A molecule with a slight positive end and a slight negative end due to uneven electron distribution.

Cohesion

Attraction between molecules of the same substance.

Adhesion

Attraction between molecules of different substances.

Mixture

A combination of two or more substances that are physically combined but not chemically combined.

Solution

A mixture where all components are evenly distributed.

Acids

Compounds that form H⁺ ions in a solution.

Bases

Compounds that produce hydroxide (OH⁻) ions in solutions.

Buffers

Substances that help prevent sudden changes in pH by reacting with added acids or bases.