Problem 1 - 43 Years JEE ADVANCED (1978-2020) + JEE MAIN Chapterwise & Topicwise Solved Papers Chemistry

Question

The atomic number of the element unnilennium is : [Main Sep. 03, 2020 (I)] (a) 109 (b) 102 (c) 108 (d) 119

Step-by-Step Solution

Answer

The atomic number of unnilennium is 109, option (a).

Step 1: Understanding the Problem

We need to determine the atomic number of the element unnilennium. In the IUPAC naming convention for unnamed elements, the prefix 'un' corresponds to the digit 1, 'nil' corresponds to the digit 0, and 'enn' corresponds to the digit 9.

Step 2: Decoding the Name 'Unnilennium'

The name 'unnilennium' can be decoded using the IUPAC temporary nomenclature: 'un' = 1, 'nil' = 0, 'enn' = 9. Therefore, the atomic number of unnilennium is 109.

Step 3: Choose the Correct Option

After decoding, we find that the atomic number of unnilennium is 109. Hence, the correct option is (a) 109.

Key Concepts

IUPAC Naming Convention

In the world of chemistry, the International Union of Pure and Applied Chemistry (IUPAC) plays a crucial role in standardizing names for elements and compounds. This ensures consistent communication among scientists globally. Understanding the IUPAC naming convention helps in identifying the properties and atomic structure of elements.
The IUPAC convention provides a systematic way to name new elements using a combination of specific prefixes. These prefixes are derived from Latin and Greek numbers. For example:

• 'un' stands for the digit 1
• 'nil' represents the digit 0
• 'enn' corresponds to the digit 9

This standardization applies especially to elements that have not yet been discovered or officially named. When an element is initially identified, an IUPAC name is allotted to avoid confusion. This standardized system helps scientists communicate more effectively and advance their research.

Unnamed Elements

Before elements receive their official scientific names, they are often referred to by temporary names. These unnamed elements are part of ongoing research. Naming follows strict IUPAC conventions, ensuring each is recognized regardless of language or region.
This temporary name system provides clarity during the initial phases of discovery. For instance, before an element receives its permanent name like 'Copper' or 'Gold', it might have carried a placeholder IUPAC name based on its atomic number.
Unnamed elements are crucial in scientific advancements. They are often at the heart of cutting-edge experiments, pushing boundaries to lead to the discovery of new elements and hence, the expansion of the periodic table. The placeholder names allow researchers to discuss new elements clearly even before final verification or naming occur.

Temporary Nomenclature

Temporary nomenclature is an essential part of chemistry, providing systematic labels for elements before they receive their definitive names. This system is used when elements are discovered but not yet officially named. Through this, scientists across the globe can communicate effectively about new discoveries without misunderstanding.
The temporary names often use the IUPAC naming system to denote the atomic number of these elements, as demonstrated by the name 'unnilennium'. This name translates to an atomic number, 109, using prefixes:

• 'un' = 1
• 'nil' = 0
• 'enn' = 9

This provides an immediate understanding of the element's place in the periodic table. Such nomenclature is temporary and is in use until the element is officially recognized and named. It enhances discussions and documentation of scientific research, ensuring all scientists can understand what is being referenced until a formal name is decided.