the Periodic Law
When the elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties

the Periodic Table
an arrangement of all known elements in a table,
in columns (or groups) of similar properties,
in rows of increasing atomic numbers

Period
each horizontal row

Group
Each vertical column contains a Group (or Family) of elements.

There are 18 columns.  Each column is numbered.

Groups contain
—elements of similar chemical properties
—properties increase in intensity going down the column

The Representative or Group A Elements
The elements in the first two columns on the left are labeled
1 (1A) & 2 (2A)

The last six columns on the right are labeled
13 (3A), 14 (4A), 15 (5A), 16 (6A), 17 (7A) & 18 (8A)

The Transition Elements or Transition Metals
The elements in the columns between 2 (2A) and 13 (3A)—
groups 3-12

Classification of Groups
 

Group 1A

the Alkali Metals

(does not include H)

.

lithium Li sodium Na (natrium) potassium K (kalium) rubidium Rb cesium Cs francium Fr

soft, shiny metals good conductors of heat and electricity relatively low melting points react vigorously with water form white products when combined with oxygen

.

Group 2A

the Alkaline Earth Metals

.

beryllium Be magnesium Mg calcium Ca strontium Sr barium Ba radium Ra

shiny metals not as reactive as Group 1

.

Group 7A

the Halogens

(At is a metalloid)

.

fluorine F chlorine Cl bromine Br iodine I

gases strongly reactive form compounds with most elements

.

Group 8A

the Noble Gases

(Og has not been tested)

.

helium He neon Ne argon Ar krypton Kr xenon Xe radon Rn

quite unreactive—“stand alone” seldom found in combination with other elements

.
the 8A elements are unreactive because they have a full outer electron shell; they do not share—give or take—electrons

Group 1A and Group 7A are the most reactive elements because they either can lose or need just one electron
.
Metals, Nonmetals & Metalloids
the zig-zag line separates metals from non metals

Metals
shiny solids
ductile
malleable
good conductors of heat & electricity
usually melt at high temps (not all)
all are solid at room temperature
—except mercury, Hg (Hydrargyrum), liquid

Examples:

Na, Mg, Cu

tin  Sn (stannum)
gold  Au (aurum)
iron  Fe (ferrum)

Nonmetals
not very shiny
not malleable
not ductile
poor conductors of heat & electricity
typically low melting points
low densities
many are gases—and one (bromine) is a liquid at 20°C

Examples:
hydrogen—H, oxygen—O, carbon—C, nitrogen—N,
chlorine—Cl, sulfur—S

Metalloids (except Al—aluminum)
elements that are on the zig-zag line—
B, (not Al), Si, Ge, As, Sb, Te, (Po), & At

properties of both metals & nonmetals
better than nonmetals of conducting heat and electricity
     (but not even close to metals)
can be brittle
higher melting points than non-metals

Inner Transition Metals
Common Properties of the Inner Transition Metals (AKA the Rare Earth Elements)

These common properties apply to both the lanthanides and actinides.
Inner Transition Metals share many common properties, making them difficult to separate or even distinguish from one another:

silver, silvery-white, or gray metals
high luster, but tarnish readily in air
high electrical conductivity
very small differences in solubility among them
occur together naturally in minerals How are the elements in a Group related?
 

Practice Problems Answer the following questions:

1. Use the Periodic Table to name and then classify each of the following elements by its group and period,  group name (if any),  and as a metal, nonmetal, or metalloid. . a)  Na b)  Si c)  I d)  Sn .

2. Give the name and symbol of the element represented: . Group 5A (15), Period 3 . A noble gas in Period 2 . A metalloid in Period 3