Problem 28 - A Complete Resource Book in Chemistry for JEE Main

Question

The electronic configuration of four different elements is given below. Identify the group IV element among these. (a) \([\mathrm{He}] 2 \mathrm{~s}^{1}\) (b) \([\mathrm{Ne}] 3 \mathrm{~s}^{2}\) (c) \([\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{2}\) (d) \([\mathrm{Ne}] 3 \mathrm{~s}^{2} 3 \mathrm{p}^{5}\)

Step-by-Step Solution

Answer

The Group IV element is configuration (c) [ Ne] 3s^2 3p^2[.

Step 1: Understand Group IV Element

The group IV elements are located in the 14th group of the periodic table and typically have four valence electrons. Their valence electron configuration is usually ns2 np2.

Step 2: Analyze Each Given Configuration

Examine each electronic configuration to determine the number of valence electrons and match it with the characteristics of a Group IV element. - (a) [ He] 2s^1[: Valence electrons [: 1 - (b) [ Ne] 3s^2[: Valence electrons [: 2 - (c) [ Ne] 3s^2 3p^2[: Valence electrons [: 4 - (d) [ Ne] 3s^2 3p^5[: Valence electrons [: 7.

Step 3: Identify the Group IV Element

From Step 2, we see that configuration (c), \([Ne] 3s^2 3p^2\), has four valence electrons which aligns with the characteristics of a Group IV element.

Key Concepts

Periodic Table

When we talk about the periodic table, we are referring to the beautiful chart that arranges all known elements in a logical order based on their properties. The table is divided into rows called "periods" and columns called "groups". Elements in the same group have similar characteristics, which means they often behave the same way chemically.

The periodic table helps predict the properties of new elements and their compounds. Scientists use it as a tool to understand how different elements interact and why they behave a certain way.

• Periods: Each row represents a period, showing how many electron shells an element has.
• Groups: Columns indicate groups, where elements have the same number of electrons in their outer shell, called valence electrons.
• Atomic Number: Elements are ordered by their atomic number, which is the number of protons in an atom.

Knowing where an element is located on this table gives insight into its potential reactions and properties.

Valence Electrons

Valence electrons are the electrons that are found in the outermost shell of an atom. They play a crucial role in the chemistry of any element, because they are involved in forming bonds with other atoms. The number of valence electrons determines how an element will react and what kind of bonds it will form.

• Bond Formation: Atoms strive to have full outer shells, often leading to sharing (covalent bonds), taking, or giving (ionic bonds) of electrons.
• Stability: Elements are most stable when their valence shell is complete, often following the octet rule, which states having 8 valence electrons brings stability.
• Groups and Valence Electrons: In the periodic table, each group (vertical column) of elements has the same number of valence electrons. For example, all Group I elements have 1 valence electron.

Understanding valence electrons is key to making sense of chemical reactions and predicting how substances will interact.

Group IV Elements

Group IV elements are found in the 14th column of the periodic table and are known for having four valence electrons. This group includes some well-known elements like carbon, silicon, and germanium. Having four valence electrons means these elements have a unique capability to form covalent bonds with other elements easily.

The ability to form bonds with many elements makes Group IV elements especially important in organic chemistry, semiconductors, and materials science.

• Chemistry of Carbon: Carbon is unparalleled in its ability to bond covalently with other elements, leading to a virtually limitless number of compounds.
• Silicon in Technology: Silicon is integral to electronic devices due to its semiconducting properties. It forms the backbone of most computer chips.
• Properties: Group IV elements tend to have a mix of non-metal and metalloid properties, contributing to their diverse range of applications.

Understanding these elements' electronic configuration can explain many of their chemical and physical properties.