Definition : What are Post-Transition Metals
The post-transition elements in the periodic table are a group of elements located between the transition metals (to the right) and metalloids (to the left). Due to their properties, they are also called ‘other’ or ‘poor’ metals .
Location of the Post-Transition Metals in the Periodic Table
Although there are some conflicting theories, generally the post-transition metals include elements from groups 13-15 [1,2].
List of Post-Transition Metals
The elements 113-116 on the periodic table, i.e. nihonium (Nh), flerovium (Fl), moscovium (Mc), and livermorium (Lv), are considered to possibly belong to the post-transition metal family, though it is yet to be confirmed due to some unknown properties of the elements .
Polonium is sometimes also included in the list of post-transition metals. The same may be done for zinc, cadmium and mercury (otherwise considered as transition metals), and for germanium and antimony (otherwise considered as metalloids) .
Properties and Characteristics of Post-Transition Metals
- Soft or brittle, poor mechanical strength 
- Melting points lower than transition metals
- Boiling points are also usually lower than transition metals 
- Covalent or directional bonding shown by crystalline structures 
- High density 
- Tendency to form covalent bonds 
- Acid – Base amphoterism
- Can form half-metallic compounds 
Periodic Trends of Post-Transition Metals
Generally, atomic radii decrease, ionisation energies increase, as a result fewer electrons are available for metallic bonding, and so ions are smaller, more polarising and tend to form covalent bonds. Hence they show lesser metallic nature .
Uses of Post-Transition Metals
Different elements in this family have different uses. Aluminium and Tin are respectively used for making utensils, in electronics, as well as for soldering and plating steel . Bismuth is used to make Pepto-Bismol, a drug used to soothe upset stomachs [1,5]. Indium is used for electronics, for example, making touch screens and flat panel displays, while Gallium has application in semiconductors and fuel cells [1, 2]. Lead is used in making batteries, among other things.
- Aluminium is the most abundant post-transition metal, and the third most abundant element on earth .
- The post-transition metal bismuth was considered to be the heaviest stable element until recently, before it wasdiscovered to be mildly radioactive.