Problem 130 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following names can be used for group VIII A elements? (a) Rare-earths (b) Inert gases (c) Rare gases of atmosphere (d) Noble gases

Step-by-Step Solution

Answer

Correct names for group VIII A elements are "Inert gases," "Rare gases of atmosphere," and "Noble gases."

Step 1: Identify Group VIII A

Group VIII A elements in the periodic table are known for their lack of reactivity. These elements are commonly referred to as the "noble gases." They occupy the far-right column of the periodic table.

Step 2: Analyze Given Options

We need to determine which of the provided names can correctly describe group VIII A elements. The options given are: (a) Rare-earths, (b) Inert gases, (c) Rare gases of atmosphere, and (d) Noble gases. We will evaluate each term's alignment with the characteristics of group VIII A elements.

Step 3: Evaluate "Rare-earths"

The term "Rare-earths" refers to a group of metallic elements found in the lanthanide series, not to group VIII A elements. Thus, option (a) is incorrect.

Step 4: Evaluate "Inert gases"

The term "Inert gases" is commonly used to describe group VIII A elements. These gases are known for their minimal reactivity, aligning with the name "inert." Thus, option (b) is correct.

Step 5: Evaluate "Rare gases of atmosphere"

The phrase "Rare gases of atmosphere" could refer to group VIII A elements, as they exist in small amounts in the atmosphere, so option (c) could be correct.

Step 6: Evaluate "Noble gases"

The term "Noble gases" is the most correct and widely accepted term for group VIII A elements because of their stability and chemical inertness, thus making option (d) correct as well.

Key Concepts

Periodic Table

The periodic table is a vital tool in chemistry, helping to categorize elements based on their properties. Each vertical column in the table is called a "group." Elements within a group often share similar properties. The periodic table arranges elements in order of increasing atomic number, and it reveals patterns among elements.
This organizational system allows chemists to understand element reactivity, electron configuration, and chemical behavior in reactions. Group VIII A, located on the far right of the periodic table, includes the noble gases.
These elements are unique because they exhibit a full valence shell of electrons, which results in their notorious lack of chemical reactivity.

Group VIII A Elements

Group VIII A elements, also known as noble gases, include helium, neon, argon, krypton, xenon, and radon.

• These elements are called "noble" due to their resistance to forming compounds with other elements.
• The term "inert gases" is another name sometimes used because these gases do not tend to participate in chemical reactions.
• They are found in trace amounts in the Earth's atmosphere, with argon being the most abundant of the noble gases in the air.

Their electron configuration is stable, as they typically have eight electrons in their outer shell, corresponding to the octet rule.
This stability is the primary reason for their chemical inertness.

Chemical Reactivity

Chemical reactivity refers to the tendency of a substance to engage in chemical reactions. Noble gases are marked by their minimal reactivity due to a completely filled valence shell. In contrast, other elements react to achieve stability by gaining or losing electrons to complete their valence shell.
Noble gases like neon and helium do not participate in such processes under normal conditions, making them unique compared to other groups on the periodic table. However, under extreme conditions, some noble gases can form compounds, primarily with elements that have a strong ability to attract electrons, like fluorine.
This highlights the importance of understanding electron configuration and stable formations in predicting the chemical behavior of elements.