The periodic table organizes the elements in a particular way. You can predict the physical and chemical properties of an atom by looking at its placement on the Periodic Table. You can also predict how an element will react with another element based on their placements. Let’s take a look at some of the characteristics of the periodic table.

Each column in the periodic table is numbered. There are 18 main columns of elements. Columns are called groups or families. Elements within the same families have similar but not identical properties. For example, lithium (Li), sodium (Na), potassium (K) and other members of Family 1 are all soft, white, shiny metals. They are all highly reactive elements and readily combine with other elements to form compounds.

Each horizontal row of elements is called a period. Unlike the elements in a family, the elements in a period are not alike in properties. In fact, the properties of the elements change greatly across any given row. But there is a pattern to the properties of the elements as one moves across a period from left to right. For instance, the first element in a period is always an extremely active solid. The last element in a period is always a particularly inactive gas.

Metals - look at the zigzag line running down the periodic table like steps. Everything to the left is a metal. Nonmetals -everything to the right of the black line is a nonmetal. Metalloids – the word means metal-like. Some act like metals and some do not. Some act like metals sometimes and like nonmetals at other times.

Family 1 – alkali metals Family 2 – alkaline earth metals Family 3 – 12 – transition metals Family 13 – boron family Family 14 – carbon family Family 15 – nitrogen family Family 16 – oxygen family Family 17 – halogen family Family 18 – noble gases

Family 1 – alkali metals: All elements in the alkali metal family have one valence electron. They are all soft, silver-white, shiny metals, and can be cut with a knife and conduct electricity With only 1 valence electron, they bond readily with other substances. These elements are never found uncombined in nature. In the lab, samples are stored in oil to keep them from bonding with other substances. Otherwise they will bond readily with water (H2O) in a violent explosion. Hydrogen is not a member; it is only listed in this family because of its electrons.

Family 2 consists of the six elements known as the alkali earth metals. These metals are never found uncombined in nature, and exist only as compounds. The alkali earth metals have 2 valence electrons, and lose them easily when combining with other atoms. They are not as reactive as alkali metals. They are all white and malleable metals that conduct electricity.

Transition metals have properties similar to one another and to other metals, but they are different from the properties of any other family. Most transition elements have 1 or 2 valence electrons. When they combine with other atoms, they either lose 1 or both of their valence electrons, or share electrons with other atoms. They are all good conductors of heat and electricity. Some are used in jewelry.

The boron family is the family of elements that have 3 valence electrons. Boron is a metalloid, as are other elements in the boron family.

The carbon family is Family 14. Atoms of this family have 4 valence electrons. Some are metals (such as tin and lead), some are nonmetals (such as carbon) and some are metalloids (such as silicon and germanium).

The nitrogen family is Family 15. The atoms of this family have 5 valence electrons in their outermost energy level. These atoms tend to share electrons when they bond with other atoms.

The oxygen family is Family 16. Atoms of this family have 6 valence electrons. Most elements in this family share electrons when they form compounds. Elements in this family are very reactive.

The halogen family is Family 17. Halogens have 7 valence electrons, which explains why they are the most active nonmetals. Atoms of these elements need to gain only 1 electron to fill their outermost energy level. The great reactivity of the halogens explain why they are never found free in nature.

Family 18 is the noble gases. All of the elements in this family are normally nonreactive. Only under special conditions do they form compounds with other atoms. As their outer electron energy level is full, they do not need to bond with other atoms to fill their energy levels. All of these are gases. All noble gases have 8 in their outer shell, except helium, which only has 2. (More on that later.)

Lanthanoids – made up of soft malleable metals that have a high luster and conductivity, and are silver or silver-gray. Actinoids – all actinoids are radioactive. Only thorium (Th) and uranium (U) are found in any abundance in nature.