The Periodic Table (Section 2.9; page 62)

The periodic table is a tabular arrangement (chart) of all the known elements, so as to provide information on the properties of the elements.  

Each element has a unique name and is represented in the periodic table by a symbol, which most often is based on the English or Latin names of the elements.

Element:  (Ebbing; 5th ed.)

(a) a substance that cannot be decomposed by any chemical reaction into simpler substances.

(b) a type of matter composed of only one kind of atom, each atom of a given kind having the same properties.

(c) a substance whose atoms all have the same atomic number.

The periodic table is a chart which organizes the elements into groups which have roughly similar properties.

The periodic table is a chart of the elements arranged by increasing atomic number so that elements in a given group have similar chemical properties.

The periodic table is composed of vertical columns called groups and horizontal rows called periods.

The periodic table is divided into groups (vertical columns) and periods (horizontal rows).

Elements are placed in the periodic table in order of increasing atomic number (Z).

Groups (or families) are vertical columns.
    Group 1A  Alkali metals
    Group 2A  Alkaline Earth Metals
    Group 7A  Halogens
    Group 8A  Noble Gases
    Groups 3-10 Transition metals

The transition metals take their collective name from their role as a bridge between the chemically active metals of Groups 1A and 2A and the much less active metals of groups 12, 13, and 14.

Groups 1A, 2A, 3A - 8A are referred to a main group elements.

Periods are horizontal rows.
There are 7 periods in the present day periodic table.

The long block below the main table consists of the inner transition metals.
    La - Yb Lanthanides
    Ac - No Actinides

The Chemical Elements  (Section 1.10)
Of all the elements in the periodic table, the vast majority are metals.  18 are nonmetals and 6 are metalloids (semimetals).

The properties of metals include luster, conductor of heat and electricity, malleable (hammered), ductile (drawn into wire). At room temperature all of the metals are solid, except mercury.

The properties of the nonmetals contrast with those of the metals.

Metalloid or semimetal can have both metallic and nonmetallic properties.  They are B, Si, Ge, As, Sb, & Te.

Br and Hg are the two elements that are liquids at room temperature.

11 elements are gases at room temperature.  H₂, He, N₂, O₂, F₂, Ne, Cl₂, Ar, Kr, Xe, Rn

7 elements exist as diatomic molecules (BrINClHOF)  Br₂, I₂, N₂, Cl₂, H₂, O₂, F₂

Allotropes are different forms of the same element that exist in the same physical state at the same temperature
and pressure.  Oxygen, O₂, and ozone ,O₃, are example of allotropes.