[Chemistry Class Notes] Metallic Character of Transition Metals Pdf for Exam

Transition metals are actually the various chemical elements that have valence electrons. It means electrons that can promote the formation of chemical bonds in two shells instead of just one. Although the term transformation does not have any specific chemical meaning, it is a convenient name for distinguishing the similarity of the atomic structures and the resulting properties of the elements. They occupy the center portions of the periodic table of elements between the groups on the left and the groups on the right. Specifically, groups 3 (IIIb) through 12 (IIb)

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What is a Metallic Character? 

According to the metallic character definition, Metallic character refers to the level of the metal’s reactivity. Metals tend to lose electrons in chemical reactions, as implied by their low ionization energy. Metal atoms have a low attraction for electrons within the compound, as indicated by their low electronegativity.

Physical properties related to metallic character involve metallic luster, glossy appearance, high density, high electrical conductivity, and high thermal conductivity. Most of the metals with metallic characters are malleable and ductile and can be deformed without breaking. In this case, Zn, Cd, Hg, and Mn are exceptions. The rest of the elements show one or more metallic characters at room temperature. Except for the metals which are exceptions, the remaining of the elements are hard and have low volatility.

Metallic Character Trend 

According to the modern periodic table, the metallic character of an element decreases as we move from left to right in the periodic table. This is due to the fact that, while moving from left to right in a period of time, the number of electrons and protons in an atom is expected to increase, which makes the nuclear force stronger, and therefore it becomes more difficult to lose electrons.

Metallic character increases down the group. This kind of metallic character trend happens because the atomic radius increases while moving down the group, which makes it easier to lose electrons.

How to Recognize Elements with Metallic Trends?

• Metallic characters are shown by metals, all of which are on the left side of the periodic table.

• The only exception is hydrogen, which is a non-metal under normal conditions. Yet hydrogen behaves like metal when it’s liquid or solid, but perhaps you should perceive it non-metallic for most purposes.

• Metallic elements occur in certain groups or columns of elements, including alkali metals, alkaline earth metals, transition metals (including lanthanide and actinides below the main body of the periodic table), and base metals.

• Other metal categories encompass base metals, noble metals, ferrous metals, heavy metals, and precious metals. Metalloids display some metallic character. However, this family of elements also has some non-metallic properties.

What are Transition Metals?

The metals in the periodic table that mostly consist of the d-block transition elements possessing unique and useful properties are known as transition metals. There are a total of 56 transition elements present in the periodic table which are further classified into three main groups-

There are incomplete inner electron shells in the case of transition metals which act as the transitional links between the most electropositive and least electropositive between the series of elements. The characterization of the transition metals can be done by the points listed below-

Transition Metals – Metallic Character

Transition metals possess low ionization energies and several vacant orbitals are present in their outermost shell. This is the reason behind their metallic character. Typical metallic properties are exhibited by transition metals because of the formation of metallic bonds between them. The presence of covalent bonds is indicated by the hardness that these metals possess which is because they have unpaired d-electrons. The unpaired electrons which are present in the d-orbitals may overlap leading to the formation of covalent bonds.

 

The number of covalent bonds present depends on the number of unpaired electrons. If the number of unpaired electrons is high, the covalent bonds will be formed more. This property leads to an increase in the hardness and strength of the metal. 

The transition metals including chromium, molybdenum, and tungsten are known to be very hard metals because they have the maximum number of electrons present in their d-orbital while on the other hand metals like mercury, zinc, and cadmium are not at all hard since no unpaired electrons are present in their d-orbitals. 

The metallic depends upon the easiness of a metal with which it loses electrons. When we move left to right across the periodic table, there is an increase in the number of protons and electrons which further leads to an increase in nuclear forces on the electrons which makes it difficult for them to lose electrons, therefore the metallic character while moving left to right decreases. As the atomic radius is increased there is an increase in the metallic character as well. Therefore while moving top to bottom, the metallic character of the elements is increased. 

Explanation for the Metallic Character of Transition Elements

• Transitional elements have a metallic character because they have low ionization energies as well as several empty orbitals in their outer shells. Such a property leads to the formation of metallic bonds in transition metals and hence demonstrates common metallic properties.

• These metals are hard, indicating the presence of covalent bonds. This is due to the presence of unpaired d-electrons in transition metals. The d-orbital containing unpaired electrons can sometimes overlap and establish covalent bonds. The higher the number of unpaired electrons present in the transition metals, the greater the number of covalent bonds formed by them.

• The chromium (Cr), tungsten (W) and molybdenum (Mo) metals have a maximum number of unpaired d-electrons. These transition metals are therefore exceedingly difficult. On the other hand, zinc (Zn), cadmium (Cd), and mercury ( Hg) are not extremely hard because they do not have unpaired d-electrons.

Metallic character with Alloys 

Although the metallic character is mainly related to pure elements, alloys could also have a metallic character. For example, bronze and most copper, magnesium, aluminum, and titanium alloys usually show a high level of metallicity. A few other metallic alloys consist purely of metals, but most often contain metalloids and nonmetals, while retaining the properties of metals.

Example Questions 

1. Give some examples of metals that display metallic character 

The metals that display with metallic characters are francium, caesium, sodium, copper, silver, iron, gold, aluminum, etc. Caesium and francium are the elements that display the highest metallic character.

 

2. How does the atomic radius vary in the metallic trends of transition elements? 

The atomic radius increases by going down a group, by moving the outer electrons further away from the nucleus. It makes the electron less attracted to the nucleus. As a result, metals become more reactive as we go down the group.