Atomic Structure and Ions Notes

Vocabulary flashcards covering key definitions and concepts related to atoms, ions, subatomic particle calculations, and Bohr models.

Atom

The basic unit of a chemical element (e.g., a hydrogen atom).

Ion

An atom or molecule with a net electric charge due to the loss or gain of electrons (e.g., sodium ion, $\text{Na}^+$).

Cation

A positively charged ion (e.g., calcium ion, $\text{Ca}^{2+}$).

Anion

A negatively charged ion (e.g., chloride ion, $\text{Cl}^-$).

Atomic number

The value that indicates the number of protons in an atom or ion.

Number of neutrons (calculation)

Determined by subtracting the atomic number from the atomic mass ($\text{atomic mass} - \text{atomic number}$).

Number of electrons in a neutral atom

The quantity of electrons that is exactly equal to the number of protons in a neutral atom (e.g., carbon has $6$ protons, $6$ neutrons, and $6$ electrons).

Number of electrons in ions (calculation)

Equal to the number of protons minus the charge for cations, and plus the charge for anions (e.g., $\text{Na}^+$ has $11$ protons, $12$ neutrons, and $10$ electrons).

Bohr model for atoms

A representation drawn with the nucleus containing the number of protons and neutrons, surrounded by electron shells where electrons are placed according to rules ($2$ in the first shell, $8$ in the second shell, etc.).

Bohr model for ions

A representation drawn with the nucleus containing protons and neutrons, surrounded by electron shells where electrons are placed according to standard shell rules while adjusting for the charge of the ion.