Cliques of the Periodic Table

 When Mendeleev began organizing the elements there were only 60 identified named elements. Now in the modern periodic table there are 112 named elements represented. These 112 elements are generally identified as either metals, nonmetals, or metalloids. 80% of the elements are metals (shiny elements that conduct heat and electricity well), 15% of the elements are nonmetals (poor conductors of heat and electricity), and the remaining elements are unique  in that that they share properties of metals and nonmetals called metalloids. These metalloids create a staircase shape in the periodic table as seen in the purple shaded area below.

Metals, Nonmetals, Metalloids

As was previously stated the periodic table is organized in both rows and columns. The columns are referred to as groups and indicate elements with similar chemical and physical properties. The modern periodic table consists of 18 of these cliques and we are going to take a closer look at each of these groups.

Periodic Table Groups

Group 1: Alkali Metals
Examples: lithium, sodium, potassium
Alkali Metals are highly reactive and not usually found freely in nature. They have only one valence electron and get their name from the highly alkaline substances, sodium hydroxide, they produce when reacting with water.

Group 2: Alkaline Earth Metals
Examples: magnesium, calcium, barium
Alkaline Earth Metals are less reactive than the group 1 metals and they are not usually found alone in nature. They have two valence electrons which they yield in chemical reactions. Common substances that contain Alkaline Earth Metals include seashells (calcium carbonate) and gemstones like aquamarine (beryllium).

Group 3: Lathanoids and Actinoids
Examples: actinium, uranium
This group includes shiny metals and radioactive elements. Lathanoids are abundant in the Earth's curst but are difficult to separate from their compounds while Actinoids are radioactive and are made in nuclear reactors. For of the Actinoids are found naturally however; actinium, thorium, protractinium, uranium.

Groups 4-12: Transition Metals
Examples: iron, nickel, gold, silver
Transition metals are all shiny metals and can be found naturally. They are however less reactive than groups 1 and 2.

Group 13 (some in 14-16): Metals
Examples: tin, lead, bismuth
Metals are harder and denser than those in groups 1 and 2 while they are softer and less dense than the transition metals. They can exist freely once refined but they are most often found as compounds in nature.

Group 17: Halogens
Examples: fluorine, bromine, iodine
Halogens are a group of similar non-metals. These elements are too reactive to occur freely in nature. The most characteristic chemical feature of the halogens is their ability to oxidize.

Group 18: Nobel Gases
Examples: helium, neon, xenon
Nobel gages are often called inert gases as well because they don't react with other elements. This is because their highest energy levels are full and they do not tend to share their valence electrons with other elements.