The periodic table of elements is divided into columns, which are referred to as groups. The main and subgroups are considered subdivisions. The elements of the same groups have similar properties and the same number of valence electrons.
Alkali metals (1st main group) are shiny, reactive metals (except hydrogen) that have a single electron in their valence shell, which they can easily give up as strong reducing agents.
Noble gases (8th main group) are monoatomic, colorless and odorless gases under normal conditions. In noble gases, all electron shells are either completely filled with electrons or empty. Therefore, this state is also called noble gas configuration.
Alkaline earth metals (2nd main group) are shiny, reactive metals with two valence electrons. They form strong bases (alkali metals) and are poorly soluble in water (earth metals).
Elements of the boron group (3rd main group, also triels) have decreasing melting and boiling points downwards, but increasing densities. At very low temperatures, metals of this group conduct electrical current without resistance.
Elements of the carbon group (4th main group, also tetrels) show very different chemical and physical properties because the group is split into two parts by the dividing line between metals and non-metals.
In the nitrogen group (5th main group), the naturally occurring elements nitrogen, phosphorus, arsenic, antimony and bismuth, as well as the extremely unstable transuranium moscovium, which does not occur in nature, are summarized.
Chalcogens (6th main group) have graded physical properties (density, melting and boiling points increase) according to increasing atomic mass. They react with metals to form earthy and partly also basic metal chalcogenides.
Halogens (7th main group) are very reactive non-metals in their elemental state. They occur in nature mainly as singly negatively charged anions in salts. Elemental halogens are colored, easily volatile to gaseous water-soluble substances.
Elements of the scandium group (3rd subgroup) have properties similar to those of the 2nd main group. Electrochemically, the elements of the scandium group are less noble than aluminum and more noble than the alkaline earth metals. The less noble character increases with increasing atomic mass.
Elements of the titanium group (4th main group) are silvery shiny metals with high melting temperatures and a typical lattice structure. They are corrosion resistant in compact form. They are resistant to many acids and alkaline reagents.
All metals from the vanadium group (5th subgroup) have similar chemical properties. Niobium and tantalum were formerly referred to as acidic earths or earth acids because of their character as acid formers.
The chromium group (6th subgroup) includes metals with similar chemical properties. As high-melting and high-boiling elements, they are important alloy components, tungsten is the metal with the highest melting point and the second highest boiling point.
Metals of the manganese group (7th subgroup) have similar chemical properties. Manganese and rhenium have technical importance as components of alloys. In organisms, manganese is involved in catalytic processes in metalloenzymes.
Iron group elements (8th subgroup) are heavy metals. According to old nomenclature, they were named as Group VIIIA or VIIIB. They have similar chemical properties and have high melting and boiling temperatures.
In the cobalt group (8th subgroup), the chemically similar elements cobalt, rhodium, iridium and meitnerium are listed. The heavy metals were also referred to as Group VIIIA or VIIIB in older definitions.
The chemically similar elements nickel, palladium, platinum and since 1994 darmstadtium are listed in the nickel group (8th subgroup). An outdated and misleading name is platinum group.
Elements of the copper group (1st subgroup) are also named as coin metals (copper, silver and gold) due to their traditional use. Higher ionization and sublimation energies result in a noble character.
Zinc group elements (2nd subgroup) often occur as sulfides (zinc blende). For extraction, the sulfides are first roasted, then reduced with carbon and finally distilled.
In the lanthanides, similar elements of the sixth period are summarized. They are silvery-shiny, relatively soft and reactive metals. The lanthanides are also referred to as rare earth metals.
All elements of the actinides are radioactive heavy metals. Due to the energy released during radioactive decay, their use in nuclear reactors and atomic weapons is significant.