Investigation 2: The Periodic Table - Enriched Chemistry

Period

Each horizontal row of elements in the periodic table

Periodic Law

States that when elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties

Group

Each vertical column of elements in the periodic table, sharing similar properties. These groups are also known as families.

Metal

A type of element that is a good conductor of heat and electric current

Nonmetal

An element that tends to be a poor conductor of heat and electric current

Metalloid

An element that tends to have properties that are similar to those of metals and nonmetals

Main Group Elements

Also called representative elements, are the elements in groups 1,2, and 13-18

Valence Electrons

Electrons in the outermost energy shell

Electron Dot Structures

Simple diagrams that show the number of valence electrons, represented as dots around the elements symbol

Colomb’s Law

The strength of the force between two charged particles (the Colombic force) depends on the charge of each particle and the distance between them

Shielding Effect

Valence electrons do not receive the full attractive force of the nucleus charge (from the positively charged protons) because the core electrons shield some of it from the valence electrons

Effective Nuclear Charge

The net positive nuclear charge experienced by an electron in an atom

Atomic Radius

One-half the distance between the nuclei of two atoms of the same element

Ion

An atom or group of atoms that has a positive or negative charge

Cation

An atom that loses one or more electrons to form an ion with a net positive charge

Anion

An atom that gains one or more electrons to form an ion with a net negative charge

Ionization Energy

The energy required to remove the outermost electron from the ground state of a gaseous atom

Electron Affinity

The energy change that happens when an atom gains an electron