Atoms and Molecules
Bonds and Octet Rules
VISUAL AIDSFunctional Groups
QUIZZESPractice Quiz I
Practice Quiz II
Practice Quiz III
Periodic Table of the Elements
Scientists use the periodic table to classify the various elements that make up all matter in the universe.
Below is an interactive periodic table with all 118 known elements known to man. If you click on the atomic symbol of any element, you will learn its chemical name and other information about its physical properties.
The modern periodic table is organized by atomic structure. There are two main aspects of the periodic table: rows, which are called periods and columns, which are called groups.
The period in which an element appears reflects the number of main electron shells, or energy levels, in an atom of that element. So sulfur (S), which is in the third period, has three main occupied electron shells.
The group number for the main set of elements (the A group) indicates the number of electrons in the valence shell. Therefore, sulfur, a member of group 6A, has six valence electrons. The B group of elements, the transition metals, are not studied in Core Studies 7.1.