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).



·      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



·      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.)