Atomic Structure and Ionization Energy Vocabulary

Flashcards of key vocabulary and definitions from the lecture notes on atomic structure and ionization energy.

Proton number (atomic number)

The number of protons in the nucleus of an atom.

Nucleon number (mass number)

The total number of protons and neutrons in the nucleus of an atom.

Atomic radius

Measure of the size of atoms; decreases from right to left of a periodic table and increases down a group.

Ionic radius

Measure of the size of ions; increases with increasing negative charge and decreases with increasing positive charge.

Isotopes

Atoms of the same element that contain the same number of protons and electrons but a different number of neutrons.

Electronic configuration

The arrangement of electrons in an atom around the nucleus in principal quantum shells.

Principal quantum numbers (n)

Numbers used to number the energy levels or quantum shells; the higher the number, the higher the energy of the shell and the greater the distance from the nucleus.

Subshells

Divisions of the principal quantum shells, denoted by the letters s, p, and d.

Atomic orbitals

Regions within subshells that can be occupied by a maximum of two electrons.

Free radical

A species with one or more unpaired electrons.

Ionisation Energy (IE)

The amount of energy required to remove one mole of electrons from one mole of gaseous atoms of an element to form one mole of gaseous ions.

Successive ionization energy

The energy required to remove the first, second, third, etc., electron from an atom or ion.

Shielding effect

The reduction of the effective nuclear charge on the outer electrons due to the repulsion of inner electrons.

Spin-pair repulsion

The repulsion between electrons in the same atomic orbital in a subshell.