Other elements sometimes included are the group 11 metals copper, silver and gold (which are usually considered to be transition metals); the group 12 metals zinc, cadmium and mercury (which are otherwise considered to be transition metals); and aluminium, germanium, arsenic, selenium, antimony, tellurium, and polonium …

Solid

Germanium atoms have 32 electrons and the shell structure is 2.8. 18.4. The ground state electron configuration of ground state gaseous neutral germanium is [Ar].

Group 12 elements are often considered to be transition metals; however, zinc (Zn), cadmium (Cd), and mercury (Hg) share some properties of both groups, and many scientists believe they should be included in the main group. Group 3 is labelled as group IIIA in the older nomenclature (CAS group IIIB).

The metals in group IB (copper, silver and gold) are sometimes called the coinage metals. The columns with B (IB through VIIIB) are called the transition elements. The columns with A (IA through VIIIA) are called the main group elements.

The outermost electrons of the alkaline earth metals (group 2) are more difficult to remove than the outer electron of the alkali metals, leading to the group 2 metals being less reactive than those in group 1. Therefore, the attraction between the nucleus and the last electron gets weaker.

At high pressure the alkali metals potassium, rubidium, and cesium transform to metals that have a d1 electron configuration, becoming transition metal-like.

Examples of main group elements include helium, lithium, boron, carbon, nitrogen, oxygen, fluorine, and neon. Elements that are not main group elements are the transition metals (such as titanium, copper, and gold), the lanthanides (such as lanthanum and erbium), and the actinides (such as actinium and plutonium).

In chemistry and physics, the main group elements are any of the chemical elements belonging to the s and p blocks of the periodic table. Specific examples of main group elements include helium, lithium, boron, carbon, nitrogen, oxygen, fluorine, and neon.

Nonmetals: Everything else to the upper right of the staircase — plus hydrogen (H), stranded way back in Group 1 — is a nonmetal. These include carbon (C), nitrogen (N), phosphorus (P), oxygen (O), sulfur (S) and selenium (Se).

The outermost electrons of the alkaline earth metals (group 2) are more difficult to remove than the outer electron of the alkali metals, leading to the group 2 metals being less reactive than those in group 1.

Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.

Which element in group 2 is most reactive?

• The Group 2 metals become more reactive towards water as you go down the Group.
• The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive.

Noble gases

Reactivity of Group II elements increases down the group. This can be explained by the increase in ease at losing two outer electrons as we descend the group. The loss of electrons becomes easier due to the decreasing ionisation energy required.