Atoms, Molecules, Ions, and Chemical Compounds

Flashcards covering fundamental chemistry definitions, including atoms, molecules, elements, compounds, ions, and chemical bonding types based on the lecture.

Atom

A particle composed of only one individual atom, which is electrically neutral and contains an equal number of protons and electrons.

Molecule

A particle composed of multiple atoms, which can be made of the same type or different types of atoms.

Pure Element

A substance made up of only one type of atom.

Compound

A substance that is composed of different types of atoms.

Ion

A particle that contains a different number of protons and electrons, resulting in a net electrical charge.

Atomic Number

The smaller number listed for an element on the periodic table, which is always equal to the number of protons in its nucleus.

Cation

An ion with a positive charge, which occurs when a particle has more protons than electrons.

Anion

An ion with a negative charge, which occurs when a particle has more electrons than protons.

Electron Calculation Formula

The formula used to find the number of electrons in a particle, defined as $\text{Atomic Number} - \text{Charge}$.

Ionic Compound

A compound typically composed of metals and nonmetals where electrons are transferred, forming positive and negative charges.

Covalent Compound

Also known as a molecular compound, a substance usually composed of nonmetals in which electrons are shared between atoms.

Ammonium Chloride Exception

A compound composed entirely of nonmetals that is classified as an ionic compound because it is made of positive ammonium ions and negative chloride ions.