Theme 4: Periodic properties of the elements (Lecture Slides Summary)

Periodic table

An arrangement of all known elements according to increasing atomic number.

Atomic number

The number of protons in the nucleus of an atom, which determines the element's identity.

Effective nuclear charge (Zeff)

The net positive charge experienced by valence electrons, accounting for the repulsion from other electrons.

Ionization energy

The minimum energy required to remove an electron from an isolated gaseous atom or ion.

Electron affinity

The energy change associated with the adding of an electron to a gaseous atom.

Isoelectronic series

A group of ions that all contain the same number of electrons.

Valence electrons

Electrons in the outermost shell of an atom that are involved in chemical bonding.

Coulomb's law

A law that describes the electrostatic interaction between charged particles, stating that the force of attraction or repulsion is proportional to the product of the charges and inversely proportional to the square of the distance between them.

Group (in the periodic table)

A vertical column in the periodic table, containing elements with similar chemical properties.

Period (in the periodic table)

A horizontal row in the periodic table, where elements show a periodic trend in properties.

Alkali metals

Group 1 elements that are highly reactive and have similar electron configurations of ns1.

Transition metals

Elements found in the d-block of the periodic table, known for being good conductors of heat and electricity.

Noble gases

Group 18 elements that are largely unreactive due to having full valence electron shells.

Atomic radius

The measure of the size of an atom, typically the distance from the nucleus to the outermost electron.

Cation

A positively charged ion formed by the loss of one or more electrons.

Anion

A negatively charged ion formed by the gain of one or more electrons.

Electron configuration

The distribution of electrons in an atom's orbitals and energy levels.

Core electrons

Electrons in the inner shell of an atom that are not involved in bonding.

Bonding atomic radius

The effective radius of an atom when it is covalently bonded to another atom.

Nonbonding atomic radius

The radius of an atom when it is not bonded to another atom.