 Elements are arranged in rows and columns  Rows = Periods  Columns = Groups or Families

 There are 18 vertical columns of the periodic table called groups or families.  Elements in the same group or family have similar characteristics or properties.

 The horizontal rows of the periodic table are called periods  Elements in a period are not alike in properties but they allow the elements in groups to line up and down with similar characteristics  Elements increase in atomic number in the periods

 Metals are on the left  Non-metals are on the right  Atomic mass (number of protons) increases from left to right across a period

 Atomic size decreases from left to right across a period as each successive element has an added proton and electron which causes the electron cloud to be drawn closer to the nucleus

 Highly reactive metals that do not occur freely in nature  Malleable, ductile, good conductors of heat and electricity  Softer than most other metals  React strongly if they are exposed to water

 Very reactive metals that do not occur freely in nature (less reactive than family 1)  Malleable, ductile, good conductors of heat and electricity  Harder than family 1 metals and do not react easily with water

 Iron, Cobalt, and Nickel, are the only elements known to produce a magnetic field.  Malleable, ductile, and good conductors of heat & electricity

 Includes elements that are radioactive and those that are man-made, numbers 93 [Np] and higher

 These metals are ductile and malleable  Some of these solid metals have very high density, ex. Lead [Pb]

 Metalloids have properties of both metals and non-metals, including a metallic luster, & partial conductivity of heat and electricity  Used in making semi-conductor devices such as computer chips

 Nonmetals do NOT conduct electricity or heat and many are considered insulators against this conduction  Very brittle, and not malleable or ductile

 Nonmetals exist in 3 states of matter at room temperature: solid- carbon, liquid- bromine (a halogen), and gas- nitrogen  Nonmetals have no metallic luster, and do not reflect light.

 Halogens are a special group of highly reactive nonmetals  “Halogen" means "salt-former" and compounds made with halogens are called "salts“  The halogens exist in all three states of matter: solid - iodine, astatine, liquid - bromine, and gas - fluorine, chlorine

 Noble gases rarely form compounds with other elements  All exist as gases  Main use is in light bulbs