Post-Transition Metals
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 [1].
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].
Metalloids on the Priodic Table
List of Post-Transition Metals |
|
| Aluminium | Al |
| Gallium | Ga |
| Indium | In |
| Tin | Sn |
| Thallium | Tl |
| Lead | Pb |
| Bismuth | Bi |
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 [6].
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) [1].
Properties and Characteristics of Post-Transition Metals
Post-Transition Metal Example Bismuth
Physical Properties
- Soft or brittle, poor mechanical strength [3]
- Melting points lower than transition metals
- Boiling points are also usually lower than transition metals [3]
- Covalent or directional bonding shown by crystalline structures [4]
- High density [5]
Chemical Properties
- Tendency to form covalent bonds [3]
- Acid – Base amphoterism
- Can form half-metallic compounds [5]
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 [3].
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 [5]. 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.
Interesting Facts
- Aluminium is the most abundant post-transition metal, and the third most abundant element on earth [1].
- The post-transition metal bismuth was considered to be the heaviest stable element until recently, before it wasdiscovered to be mildly radioactive.
References:
- https://www.ducksters.com/science/chemistry/post-transition_metals.php
- http://www.miningoilgasjobs.com.au/mining/all-you-need-to-know-about-the-mining—metals-sec/quick-facts-about-post-transition-metals.aspx
- https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Post-transition_metal.html
- https://posttransitionmetals.weebly.com/properties-of-the-post-transition-metals.html
- https://prezi.com/c8vo6gdp78-n/post-transition-metals/
- https://schooledbyscience.com/everyday-uses-of-basic-metals/
