Periodic classification of elements, a significant part of the inorganic chemistry syllabus for NEET and JEE, isn’t usually a fan favourite of the students. Owing to the belief that it must be mugged up, without applying a lot of logic, students do not wish to study this chapter in-depth.
What they forget is that this topic can fetch them easy marks in NEET and JEE. Whether it be boards or an entrance exam, direct questions are always asked from this chapter, and it is one of the easiest parts of the syllabus if done correctly.
How to score the maximum marks possible in this chapter, then? We list 5 things that you should keep in mind.
The history of the periodic table
At first, there were the Dobereiner triads, then came Newland’s octaves, followed by the atomic table of Mendeleev. The history of the periodic table is crucial since it determines the present structure of the modern periodic table. Sometimes, even direct questions are asked from Newland’s octaves or the triads, which are easy to answer and fetch marks with minimal effort.
Exceptions in periodic properties
Perhaps the most important part of this chapter is getting the exceptions right. The elements that exhibit properties other than what they are expected to exhibit are called exceptions or anomalies. Memorizing these elements, their atomic properties, and the trends in these anomalies is very key to getting questions right.
Since there is not much scope for asking questions on such a topic in competitive exams, paper setters usually focus on the anomalies to try and trick students into marking the wrong answer.
Different periodic trends in properties
When it comes to periodic classification, remembering the trends followed by atomic properties is a must in order to fetch a good score. These properties include the ionization enthalpy of atoms, radius, electron gain enthalpy, electron affinity, and electronegativity.
Trends include a decrease in electronegativity and electron affinity from top to bottom in a group, an increase in electronegativity from left to right in a period up till group 17, and so on.
Principles of inert gases
Forming the last group of the periodic table, inert gases are important compounds with respect to periodic classification. They exhibit properties different to all other elements of the table and are thus placed separately at the end. Memorizing their properties, examples, and applications correctly might help you gain an edge over competitors.
The electronic configuration
This is one of the most basic concepts of chemistry, let alone periodic classification. Therefore, it is advised to try and make no mistakes while working with the electronic configuration of elements. Since the periodic table is divided into blocks, it is easier to study the electronic configuration of elements this way. The s, p, d, and f block elements are all named due to the presence of the last electron in the respective subshells.
Never get these five things wrong about the periodic classification of elements, and you will never lose any marks in NEET, JEE, or even boards.