Several media reports and a recent article published by the Journal Nature claim that the topics of the Periodic Table and Charles Darwin’s Theory of Evolution have been entirely dropped from the school education curriculum in India. This claim is completely misleading as the topics have not been removed but shifted from Class 10 to Class 11 (Unit 3 in Chemistry: Classification of Elements and Periodicity in Properties, Pages 74-99) and Class 12 (Chapter 6 in Biology: Evolution, Pages 110-126), respectively.
This has been clarified in a recent statement issued by the National Council of Educational Research and Training (NCERT). As stated by NCERT in a series of tweets, this exercise has been done as a part of “Rationalisation of NCERT Textbooks” aiming to reduce content load, particularly keeping in view challenges faced by the students during the Covid pandemic, which impacted students’ mental health and their learning abilities. Indeed, there is a developing consensus in the academic community that students enrolling for first-year undergraduate programs in recent years faced difficulties in coping with the university-level curriculum due to a lack of understanding of many fundamental concepts in basic sciences taught in school education. Therefore, a restructuring of the school curriculum to emphasise basic concepts and principles instead of overwhelming content is an urgent need.
NCERT has also stated that the rationalised content has been proposed as a stopgap strategy to facilitate a smooth transition in learning from pandemic to post-pandemic times. In the long term, all the textbooks will be completely revamped following National Curriculum Framework for School Education (NCF-SE) based on the vision outlined in National Education Policy (NEP) 2020. In fact, the pre-draft for the same was released in the public domain on April 6, 2023, and is currently soliciting inputs from the public. As well articulated by the Nature article, NEP 2020 emphasises the need to improve the problem-solving and critical thinking ability of students, rather than rote memorisation of the content. However, instead of focusing on this critical aspect to understand the motive behind the rationalisation, the article appears to take a political perspective by claiming that these changes are advocated by the Rashtriya Swayamsevak Sangh (RSS) and have been implemented due to their close ties with the ruling Bharatiya Janata Party (BJP). Such political comments may be considered unwarranted for a prestigious scientific journal like Nature.
The Nature article also emphasises that “the development of a scientific temperament and pride in heritage can go hand in hand.” In this context, the article advocates for alternative methods such as using visual aids like videos and animations instead of adapting rote learning approaches in cultivating scientific temperament among students. However, it appears puzzling to understand why the article fails to recognise the rationalisation of textbooks, for example, relocation of the topic of The Periodic Table from Class 10 to Class 11, as one such alternative strategy. It is a common observation of many teachers that the majority of school students in India often begin their learning of the periodic table by memorising the names of the first 20 or 30 elements without fully grasping the underlying basis of classification. The appreciation for the principles of classification typically comes rather late in classes 11 and 12, when students delve deeper into the study of individual groups and explore the shared physical and chemical properties of elements within the same group. Consequently, this traditional approach might negatively impact the interest of Class 10 students in Chemistry, as it can create an impression among them that the subject involves a lot of memorisation.
One alternative approach is to first introduce the underlying core principle behind the classification of elements into groups, namely, the same number of electrons present in the outermost shell (called valence electrons) in all elements constituting a group. This can be effectively achieved by providing specific examples of elements that exhibit similar properties due to an equal number of valence electrons.
For example, the elements sodium and potassium both have only one valence electron, explaining their shared tendency to lose exactly one electron (metals) to attain a stable configuration. Similarly, chlorine and bromine, with seven valence electrons, gain exactly one electron (non-metals) to achieve stability. By presenting these examples, students can better comprehend the formation of a chemical bond between an element with tendency to lose one electron (sodium or potassium) and one with tendency to gain one electron (chlorine or bromine). This approach reduces the reliance on memorisation and helps students inculcate an algorithmic approach to understanding the concept of chemical bonds. Moreover, it enhances the critical thinking of students by enabling them to identify patterns among the properties of different elements, and encourages them to devise their own method of classifying elements into groups. For example, upon realising that lithium, sodium, and potassium exhibit similar properties, students might be inclined to group these three elements together, a classification reminiscent of Döbereiner’s Triads proposed in 1817.
It is reassuring that the NCERT textbook of Class 9 continues to address fundamental concepts such as the electronic configuration of elements, the formation of atoms and molecules, octet rule, and the textbook of Class 10 covers metals and non-metals. By familiarising themselves with the principle that elements with an equal number of valence electrons exhibit similar properties and other above-mentioned fundamental concepts, students become well-prepared for the next step in their academic journey.
Therefore, introducing the classification of elements into groups based on this principle, The Periodic Table, in Class 11 seems a logical progression.
The author is currently working as an Assistant Professor in Department of Chemistry at SRM University, AP (can be reached at [email protected]). His major research interests include Theoretical and Computational Chemistry, and Quantum Computing. Views expressed are personal.
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