Periodic Table of Elements Grouped into families bases on their chemical properties. Each family has a specific name to differentiate it from the other families in the periodic table. Elements in each family react differently with other elements. Groups (vertical columns) Periods (horizontal rows)

Dimitri Mendeleev “ I began to look about and write down the elements with their atomic weights and typical properties, analogous elements and like atomic weights on separate cards, and this soon convinced me that the properties of elements are in periodic dependence upon their atomic weights. ” --Mendeleev, Principles of Chemistry, 1905, Vol. II

ALKALI METALS Group 1 Hydrogen is not a member, it is a non-metal 1 electron in the outer shell Soft and silvery metals Very reactive, esp. with water Conduct electricity maths-technology/science/chemistry/alkali- metals

ALKALINE EARTH METALS Group 2 2 electrons in the outer shell White and malleable Reactive, but less than Alkali metals Conduct electricity

TRANSITION METALS Groups in the middle Good conductors of heat and electricity. Some are used for jewelry. The transition metals are able to put up to 32 electrons in their second to last shell. Can bond with many elements in a variety of shapes.

Boron Family Group 13. This group includes the elements boron, aluminum, gallium, indium, and thallium. All five have three electrons in their outer energy level. Only one member of this family is a metalloid -- boron. The others are classified as metals, forming positive ions by giving up their three outermost electrons.

Carbon Family The five members are carbon, silicon, germanium, tin, and lead. All of these elements have four electrons in their outermost energy level. Silicon and germanium are semimetals (metalloids), existing in compounds with either +4 or -4 charges. Tin and lead are definitely metals. They always lose electrons due to the distance of their outer shells from the nucleus. They usually form compounds as cations with a +4 charge. All of the elements of this family can form four bonds, the most of any family.

Nitrogen family Group 15 Five electrons in their outermost energy level. Non-metals, semimetals, and metals Nitrogen and phosphorus, are very definitely nonmetals, forming -3 charge anions. Nitrogen is a diatomic gas and phosphorus is a solid. arsenic, antimony, and bismuth all have some characteristics of semimetals

Oxygen family Group 16 Oxygen, sulfur, selenium, tellurium, and polonium. Each has six of the desired eight electrons required for the octet in its highest energy level. This means that it takes or accepts two electrons from atoms of other elements to form anions or shares two electrons to form covalent bonds.

Metalloids

Have properties have both metals & non-metals Many – semiconductors (conduct electricity in special conditions) – so used in computers & calculators resources resources BoronSiliconGermanium ArsenicAntimonyTellurium Polonium

Halogens Group 7 7 electrons in the outer shell All are non-metals Very reactive are often bonded with elements from Group 1

Noble Gases Group 8 Exist as gases Non-metals 8 electrons in the outer shell = Full Helium (He) has only 2 electrons in the outer shell = Full Not reactive with other elements

Rare Earth Metals Some are Radioactive Silver, silvery- white, or gray metals. Conduct electricity lanthanides and actinides ews/world-asia-pacific ews/world-asia-pacific

Rare Earth Metals (30) The Rare Earth Metals are hardly rare at all. In fact, many of them are dirt common, but they were discovered late and people had trouble separating them. The name became established before people realized they weren't rare, and its a nice-sounding name so it stuck. ndex.html ndex.html