Problem 120 - A Complete Resource Book in Chemistry for JEE Main

Question

An element has exceptional outer electronic configuration as \(4 \mathrm{~d}^{10} 5 \mathrm{~s}^{\circ}\). It belongs to

Step-by-Step Solution

Answer

The element belongs to Group 12, Cadmium (Cd).

Step 1: Understanding the Configuration

The electronic configuration given is \(4d^{10} 5s^0\). This indicates that the element has a completely filled \(4d\)-orbital and no electrons in the \(5s\)-orbital.

Step 2: Identifying the Period and Block

Since the principal quantum number for the \(s\)-orbital is 5, this element is in the 5th period. Having electrons in the \(d\)-orbital suggests it belongs to the d-block.

Step 3: Allocating the Element to a Group

The completely filled \(4d^{10}\) suggests that the element must be one of the last elements in its period, particularly at the end of the transition series. This configuration is characteristic of group 12 elements.

Step 4: Identifying the Element

The group 12 elements are Zinc (Zn), Cadmium (Cd), and Mercury (Hg). In the 5th period, this configuration corresponds to Cadmium (Cd).

Key Concepts

d-block elements

In the periodic table, the d-block elements are also known as the transition elements. They are characterized by having their last electron added to a d-orbital. These elements are found in groups 3-12 of the periodic table. What stands out about d-block elements is their ability to form various oxidation states. That's because the energy levels of the outermost s and inner d-orbitals are close together. As a result, electrons can be easily shuffled between these orbitals when necessary.

D-block elements include metals that are known for their conductivity, high density, and, in many cases, catalytic properties. This includes precious metals such as gold and platinum as well as iron and nickel, which have practical, everyday applications.

The d-block is named based on the d-orbital, where the characteristic "d" stands for diffuse, indicating the particular electron cloud shape of this set of orbitals. These elements are central to many chemical processes and applications, including the formation of alloys and the catalysis of chemical reactions.

transition metals

Transition metals are a subset of d-block elements. They are defined by the presence of a partially filled d-subshell, or the ability to form at least one cation with an incomplete d-shell. This definition can also extend to elements like copper or zinc, which need such states in their compounds.

These metals are primarily known for their hard, durable nature, as well as their ability to conduct electricity and heat efficiently. Many transition metals can be found in everyday artifacts and are essential components of structural materials like steel and aluminum.

• They often display vivid colors in their compounds, which is due to d-d electron transitions.
• Transition metals also display catalytic properties, playing a crucial role in industrial processes and the manufacturing of products.

Of particular note, many transition metals possess magnetic properties, with iron being one of the most familiar to us. Transition metals' versatile electron configurations give them unique chemical behaviors, making them invaluable in both manufacturing and chemical research.

group 12 elements

Group 12 elements are situated in the d-block and include Zinc (Zn), Cadmium (Cd), and Mercury (Hg). Unique to group 12, these elements have a complete d-subshell in their ground state. This sets them apart from other transition metals, as they do not generally exhibit multiple oxidation states like other d-block elements.

A fascinating aspect of group 12 elements is their diverse physical states and applications:

• Zinc is a vital mineral for human health and is also used extensively in galvanization to prevent rusting.
• Cadmium is used in batteries and pigments but requires careful handling due to its toxicity.
• Mercury, the only metal at room temperature that is liquid, has historical applications in thermometers, though it's been phased out for safety reasons.

Despite being in the d-block, their chemistry is different due to filled d-orbitals, making them worth distinguishing from other transition metals in educational contexts.

periodic table

The periodic table is a systematic arrangement of chemical elements, organized based on atomic number, electron configuration, and recurring chemical properties. It allows scientists and students alike to quickly discern patterns in element properties, making it a vital educational tool.

The periodic table is divided into blocks (s, p, d, and f), groups, and periods:

• Periods: Horizontal rows that indicate the number of electron shells.
• Groups: Vertical columns where elements share chemical properties and valence electron configurations.
• Blocks: Indicate where an element's outermost electrons are held, influencing its chemical reactivity.

D-block elements, such as those found in Group 12, fit into this layout, helping predict their behaviors and characteristics. With its comprehensive structure, the periodic table is not just a list of elements; it's a powerful framework that lays the foundation for understanding chemical reactions and bonding, illustrating the interconnected nature of elements.