Difference Between Representative and Transition Elements

Key Difference – Representative vs Transition Elements
 

The periodic table of elements is a tabular arrangement of all known chemical elements based on their atomic numbers. There are rows or periods and columns or groups in the periodic table. There are periodic trends in the periodic table. All the elements in the periodic table can be divided into two groups as representative elements and transition elements. The key difference between representative elements and transition elements is that representative elements are the chemical elements in the group 1, group 2 and in the groups from 13 to 18 whereas transition elements are chemical elements in group 3 to group 12 including Lanthanides and Actinides.

CONTENTS

1. Overview and Key Difference
2. What are Representative Elements
3. What are Transition Elements
4. Side by Side Comparison – Representative vs Transition Elements in Tabular Form
5. Summary

What are Representative Elements?

Representative elements are the chemical elements in the group 1, group 2 and in the groups from 13 to 18. Representative elements are also known as “group A elements” or “s block and p block elements” or “main group elements”, meaning representative elements include the following groups of chemical elements;

• S block elements (Alkali metals and alkaline earth metals)

S block elements have their valence electrons in the outermost s orbitals and are in two types as alkali metals and alkaline earth metals along with hydrogen and helium. Alkali metals are group 1 elements (excluding hydrogen) whereas alkali earth metals are group 2 elements. These metals are named as such because they form basic or alkaline compounds. Alkali metals include Lithium, Sodium, Potassium, Rubidium, Caesium, and Francium. Alkaline earth metals include Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium.

Figure 01: Arrangement of Representative and Transition Element in the Periodic table

• P block elements (nonmetals, halogens, noble gases)

P block elements have their valence electrons in the outermost p orbitals. Almost all the p block elements are nonmetals, including some metalloid elements (excluding Helium, because it is an s block element). There are periodic trend along periods and down the groups in the p block. Metalloids include boron, silicon, germanium, arsenic, antimony, and tellurium. Noble gases are the group 18 elements (that have completed electron configurations). All others are nonmetals.

What are Transition Elements?

Transition elements are chemical elements that have unpaired d electrons at least in a stable cation that is can form. All the transition elements are metals. They have their valence electrons in the outermost d orbitals. Therefore, all the chemical elements from group 3 to group 12 are transition metals excluding zinc (because zinc has no unpaired electrons and Zn⁺² also has no unpaired electrons. Zn⁺² is the only stable cation of zinc).

Almost all the transition metals have multiple stable oxidation states in different compounds. All these compounds are very colorful. And also, the captions containing the same transition elements with different oxidation states can have different colors based on the oxidation state (the color of the cation varies with the oxidation state of the same chemical element). The reason for this color is the presence of unpaired d electrons (it allows the electrons to jump from one orbital to another by absorbing energy. When these electrons come back to the previous orbital, it emits the absorbed energy as visible light).

Figure 02: Different Oxidation states formed by Transition Metals

Lanthanides and Actinides are also named as “inner transition metals” because their valence electrons are in their f orbitals of the penultimate electron shell. These elements can be seen in the f block of the periodic table.

What is the Difference Between Representative and Transition Elements?

Summary – Representative vs Transition Elements

Representative elements are the main group elements that include alkali metals, alkaline earth metals, nonmetals and noble gases. Transition metals are in the d block and the f block of the periodic table. The difference between representative elements and transition elements is that, representative elements are the chemical elements in the group 1, group 2 and in the groups from 13 to 18 whereas transition elements are chemical elements in group 3 to group 12 including Lanthanides and Actinides.

Reference:

1.“Definition of Representative Element.” Sciencing,  Available here
2.“Transition metal.” Wikipedia, Wikimedia Foundation, 25 Feb. 2018. Available here 
3.“Representative And Transition Elements;) – A Haiku Deck by Jade Bailey.” Haiku Deck: Presentation Software and Online Presentation Tools. Available here  

Image Courtesy:

1.’PTable structure’By Sch0013r, (CC BY-SA 3.0) via Commons Wikimedia
2.’Transition metal oxidation states 2’By No machine-readable author provided. Felix Wan assumed (based on copyright claims). (CC BY-SA 3.0) via Commons Wikimedia

Related posts:

Difference Between D Block Elements and Transition Elements Difference Between Strong Ligand and Weak Ligand Difference Between Hydrogen Water and Alkaline Water Difference Between Tris Base and Tris HCl Difference Between VBT and CFT