Periodic Trends and Electron Configurations

These flashcards cover key vocabulary related to periodic trends, electron configurations, cation and anion formation, and related chemical concepts.

Valence Electrons

The electrons in the outer shell of an atom that determine its chemical properties.

Periodic Properties

Characteristics of elements that change systematically across the periodic table.

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.

Effective Nuclear Charge (Zeff)

The net positive charge experienced by an electron in a multi-electron atom, calculated as Zactual minus electron shielding.

Isoelectronic Species

Atoms and ions that have the same electron configuration.

Electron Shielding

The phenomenon where inner electrons block the outer electrons from the nuclear charge.

Transition Metals

Elements that form cations by losing s and d electrons.

Atomic Radius

The measure of the size of an atom, typically the distance from the nucleus to the boundary of the surrounding cloud of electrons.

Ionic Radius

The radius of an ion and can differ from the atomic radius depending on whether it is a cation or anion.

Periodic Trends

Patterns observed in the properties of elements across the periodic table such as atomic radius, ionization energy, and electronegativity.

Alkali Metals

A group of elements in group 1 of the periodic table known for their high reactivity and ns1 electron configuration.

Halogens

The elements in group 17 of the periodic table that are known for their strong oxidizing ability and ns2np5 electron configuration.

Noble Gases

Elements in group 18 of the periodic table that have a complete valence shell (ns2np6), making them largely inert.

Variable Charges

The ability of some main-group metals to form cations with more than one possible positive charge.