Lesson 20 - Periodicity

Flashcards covering key concepts related to periodicity, atomic and ionic radii, metallic character, and ionization energy.

Periodic Law

When elements are arranged by atomic number, their physical and chemical properties vary periodically.

Valence Electrons

Electrons in the outermost shell of an atom involved in the formation of bonds between atoms.

Valence Shell

The outermost shell of an atom that holds valence electrons.

Atomic Radius

The distance from the nucleus of an atom to the outer boundary of its surrounding cloud of electrons.

Ionic Radius

The measure of an atom's ion in a crystal lattice; it is different from the atomic radius.

Metallic Character

The level of reactivity of a metal; typically increases down a group and decreases across a period.

Ionization Energy

The energy required to remove an electron from an atom in the gas phase.

First Ionization Energy (IE1)

The energy required to remove the outermost electron from a neutral atom in the gas state.

Successive Ionization Energies

The increasing energy required to remove electrons in succession from the same atom.

Trends in Ionization Energy

Ionization energy generally increases across a period and decreases down a group.