Periodic Table

Periodic Table-  a table illustrating the periodic system.

Group-  a vertical column on the periodic table in which all elenments have the same number of electrons in outer electron shell as well as have similar properties.

Period- a horizontal row on the periodic table which starts with smallest atomic numbers on the left and gradually get larger as they move to the right and down. Also, the elements become less and less metallic as they move from left to right.

Representative Elements- Main elements of the periodic table, these are the most abundant elements in the universe.

Transition Metals- Elements in the block from group 3 through group 12 on the periodic table.

Lanthanides- 'rare earths', part of block f on the periodic table, somtimes thought of as an inner transition metals.

Actinides- radioactive metals which are apart of block f on the periodic table, sometimes thought of as inner transition metals.

Noble Gas- inert gases that don't form compound with other elements very easily. All have full outer electron shells. Known as group 18 on the periodic table, nonmetals.

Halogen- Group 17 on the periodic table, nonmetals. This group is different because it is the only group with all three states of matter within it at all times. Each element in this group has 7 electrons in its outer electron shell. All are highly reactive, Fluorine being one of the most reactive elements.  

Alkali Metal- Group 1 on periodic table. Extremely reactive metals that do not freely occur in nature. Explode when come in contact with water.

Alkaline Earth Metal- Group 2 on the periodic table, metals. Very reactive and also do not occur freely in nature. They are very soft metals and react violently with halogens to create ionic salts and water.