In the common version of the periodic table, the elements are shown in boxes in a grid. The atomic number of the element increases from left to right and going down the table. The horizontal rows are called . The vertical columns are known as . The position of the element shows two key pieces of information about an atom's . The period number shows the total number of electron . The group number shows the number of electrons in the orbit. The members of a given group often have physical and chemical properties which are and show trends in these properties with increasing atomic number.

Metals
The names of metals end in "ium" apart from which is a non-metal. Those discovered before about 1800 have irregular names but most are familiar eg gold, lead, copper, iron, zinc and nickel. All metals have structures so are at room conditions (apart from mercury which is a ). All metals appear a shade of grey with the exception of (yellow) and copper (brown); frequently they have a shiny surface (lustre). All metals have a high boiling point (above 400 C) though some, notably Group 1, have a melting point below 100 C.

Non-metals
About half are at room conditions; these are all of Group (the Noble Gases) which exist as single atoms, and the diatomic , H₂, N₂, O₂, F₂, and Cl₂. Bromine (Br₂) is also diatomic and is the only non-metallic at room conditions. The solid non-metals are often coloured. The simple molecules have a melting point below 200 C. The giant molecules (mainly Group 4) have very melting and boiling points. A number of non-metals have ; important examples include C ( and diamond), P (red and white), S (rhombic and monoclinic crystals of S₈) and O (,O₂ and , O₃).

Group 1 - the Metals
These elements have a melting point than is typical of most metals; indeed the melting point of Na is only 98 C and melting point going down the Group. Boiling point is high, meaning that the metals are in the state over a wide temperature range eg Na at 890 C. This property has led to the use of Na as a primary coolant in some reactors. The solids are and have low density; Li, Na and K are less dense than water. All are very . They are stored under oil since they tarnish rapidly in air. With cold water, all produce with increasing reactivity going down the Group.

                eg    2 Na_(s)   +   2 H₂O_(l)      ------------ >     2 NaOH_(aq)     +      H_2(g)

Compounds of the elements are , with a charge of on the metal ion. All the oxides are in water giving solutions. All group 1 compounds are white but give a distinctive to a bunsen flame.

Group 7 - the Halogens (the salt-makers)
All are diatomic elements with simple molecular structures and show clear in physical properties and chemical reactivity. They form simple covalent molecules when reacted with other and a giant lattice with a metal. (There are some important exceptions, especially at A-level, notably aluminium, iron and titanium chlorides.) The ionic charge is commonly .
has many uses. It reacts with NaOH to give NaOCl, used as bleach. With organic compounds, it is used to make hard plastics and solvents.

Group 8 - the or Inert Gases
In appearance, all are monatomic gases at room conditions and can be found in small quantities in , the commonest being at 0.9% . Melting and boiling points are very but there is a clear trend of boiling point going down the Group. The gases are very unreactive because the outer shell of electrons is full; so He, Ne and Ar have no known . Their chemical inactivity is exploited in the use of argon as an inert atmosphere in welding or to surround the filament of light bulbs.

Transition Metals
The group of elements from Sc to Zn and below are called . Compared with other metals in the periodic table, transition metals are relatively and are and ; they have melting and boiling points. Their oxides are but do not dissolve to form alkalis. Transition metal compounds show evidence in their formulae that more than one ion exists; eg Fe forms Fe²⁺ and Fe³⁺ while Mg (Group 2) forms Mg²⁺ only. This Group has compounds which often act as in chemical reactions; by contrast Group 1 and 2 compounds are white and show no catalytic activity.

Iron is a typical transition metal. It is used to make bridges and is the catalyst used in the process. It rusts slowly giving a red-brown oxide, Fe₂O₃; there are two other common oxides, Fe₃O₄ and FeO. The metal may be alloyed with others changing the properties to be more suitable for specific applications.