Vocab

Group

A vertical column of elements in the periodic table, where each element shares similar chemical properties and behaves in a related manner.

Metal

A category of elements that are typically shiny, good conductors of heat and electricity, malleable, and ductile, allowing them to be shaped without breaking.

Metalloid

An element that exhibits characteristics of both metals and nonmetals, often having a mixed set of properties that can vary depending on conditions.

Nonmetal

A group of elements that generally lack metallic luster, are poor conductors of heat and electricity, and tend to gain electrons in chemical reactions.

Period

A horizontal row of elements in the periodic table, where elements within the same period have the same number of electron shells surrounding their nucleus.

Periodic Law

The principle stating that the properties of elements tend to recur at regular intervals when the elements are arranged by increasing atomic number.

Periodic Table

A systematic arrangement of the chemical elements ordered by their atomic number, showing periodic trends in their properties, electron configurations, and relationships.

Actinide

A series of 15 elements ranging from actinium (Ac) to lawrencium (Lr) that are typically radioactive and are located at the bottom of the periodic table.

Alkali Metal

Extremely reactive metals that belong to Group 1 of the periodic table, characterized by having a single electron in their outermost shell.

Alkaline Earth Metal

Reactive metals found in Group 2 of the periodic table, known for having two electrons in their outermost shell and forming compounds with a +2 charge.

Halogen

Highly reactive nonmetals located in Group 17 of the periodic table, with seven electrons in their outer shell, leading them to readily form compounds.

Inner Transition Element

Elements located in the two rows below the main body of the periodic table, including the lanthanides and actinides, which have partially filled f subshells.

Lanthanide

A series of 15 chemical elements from lanthanum (La) to lutetium (Lu), known for their similar properties and found in the f-block of the periodic table.

Noble Gas

Colorless, odorless gases in Group 18 of the periodic table that are characterized by their very low reactivity due to having full valence electron shells.

Representative (Main-Group) Elements

Elements in Groups 1, 2, and 13-18 that showcase a variety of chemical behaviors and properties, often forming predictable chemical compounds.

Transition Element

Metals found in Groups 3-12 of the periodic table, known for their ability to form variable oxidation states and colored compounds.

Chalcogen

Elements found in Group 16 of the periodic table, including oxygen, sulfur, and selenium, known for their varied reactivity and roles in biological systems.

Pnictogen

Elements in Group 15 of the periodic table, including nitrogen and phosphorus, that exhibit diverse chemical properties and form a variety of compounds.

Anion

A negatively charged ion that is formed when an atom or molecule gains one or more electrons.

Atomic Radius

The distance from the nucleus of an atom to the outermost shell of electrons, affecting how atoms bond and interact with each other.

Cation

A positively charged ion created when an atom or molecule loses one or more electrons.

Electron Affinity

The amount of energy released when an atom gains an electron, often indicating the likelihood of the atom to form negative ions.

Electronegativity

The measure of an atom's ability to attract and hold onto electrons when it forms chemical bonds, influencing bond polarity and stability.

Ion

An atom or molecule that has gained or lost one or more electrons, resulting in a net charge.

Ionization Energy

The energy required to remove an electron from a neutral atom in its gaseous state, indicating the atom's tendency to form cations.

Law of Octaves

A historical observation that, when arranged by increasing atomic mass, elements' properties repeat every eighth element.