An element that typically has four or more valence electrons. It may be a gas, a liquid, or a dull, brittle solid at standard conditions. They are generally poor conductors, and their chemical activity is highly variable, from very reactive to inert

Elements having the same valence electron structure and often similar chemical properties. Elements in this reside in a column on the periodic table. These are named by the element at the top of the column

An element in Group 1A of the periodic table; a strongly reactive metal with an oxidation number of +1

An element in Group 2A of the periodic table; a very reactive metal having an oxidation number of +2

Group 4A of the periodic table. The elements have variable chemical activity and usually have an oxidation number of +4 or -4, depending on the other elements they bond with

Group 5A of the periodic table. The chemical activity of this group is highly variable. Several elements have as many as eight different oxidation numbers

A metal element found in the B-subgroups of the periodic table

Group 7A of the periodic table. Very chemically reactive elements that usually have an oxidation number of -1.

An element in Group 8A of the periodic table. These elements are essentially inert, monatomic gases with an oxidation number of 0.

A horizontal row in the periodic table of the elements.

Elements in the same _________ have the same number of valence electrons.

____________ determine chemical properties.

Created the first periodic table

Vertical columns in the period table.

Found along the "stair-step" of the period table.

Elements that are usually gases at room temperature.

Elements that are created by scientists in a lab are called

a law that states that the repeating chemical and physical properties of elements change periodically with the atomic number of the element.