Regions of the Periodic Table

period: a row of the periodic table. Properties of the elements are periodic, meaning that they repeat after a specific interval. Elements in the same period have their highest energy electrons in the same principal energy level.

group (family): a column of the periodic table. Elements in the same group have the same number of valence electrons, and therefore have similar chemical and physical properties.

Metals, Non-Metals & Metalloids

metals: elements to the left of and below the “stairstep line.”

non-metals: elements to the right of and above the “stairstep line.”

metalloids: most of the elements that touch the “stairstep line”. (All except for Al and Po).

Properties

metals:

· shiny

· high density

· good conductors of heat & electricity

· malleable & ductile (can be reshaped by hammering, bending and stretching)

· high melting & boiling points

· most have 3 or fewer valence electrons

· tend to form positive ions

non-metals:

· dull

· low density

· poor conductors of heat & electricity

· brittle

· low melting & boiling points

· most have 4 or more valence electrons

· tend to form negative ions

metalloids: can have properties “in between” or can have some properties like metals and others like non-metals.

Groups of Elements

alkali metals: elements in group IA of the periodic table.

· 1 valence electron (form +1 ions)

· very reactive

· soft

· very high melting & boiling points

· ions are soluble in water

alkaline earth metals: elements in group IIA of the periodic table.

· 2 valence electrons (form +2 ions)

· reactive, though not as much as group I metals

· very high melting & boiling points

· ions are not soluble in water

transition metals: elements in the center section of the periodic table.

· have a partially-filled d sub-level

· form colored ions when dissolved in water

· officially have 2 valence electrons, but can shift electrons into and out of s and d sub-levels. Often form more than one kind of ion.

· most are shiny, hard metals with high melting & boiling points

inner transition metals: elements in the “f block” of the periodic table.

· are part of the transition metals

· have a partially-filled f sub-level

· officially have 2 valence electrons, but can shift electrons between s, d, and f sub-levels. Usually form ions with +3 charges.

· are rare

halogens: elements in group VIIA of the periodic table.

· 7 valence electrons (form −1 ions)

· reactive

· diatomic (atoms in pairs) in their natural state: F₂, Cl₂, Br₂, I₂

· low melting & boiling points. (F & Cl are gases at room temp; Br is a liquid, and I is a solid, but will melt in your hand.)

· form salts that are soluble in water (except for fluorine—flouoride salts are not soluble in water.)

noble gases: elements in group VIIIA of the periodic table.

· 8 valence electrons (except for He which has 2)—full valence shells

· do not form ions

· do not react with other compounds

· gases

· extremely low melting & boiling points. (In fact, helium cannot be made into a solid even at absolute zero, except at extremely high pressures.)

courtesy of : http://www.mrbigler.com/Chem1-C1/topics/pt/PT-parts.html