"In principle and practise, the Periodic Table is possibly the most significant notion in chemistry...Anyone who aspires to detangle the world and comprehend how it is built up from the fundamental building blocks of chemistry, the chemical elements, must be familiar with the Periodic Table."
Glenn T Seaborg's statements begin the chapter on 'Classification in Elements and Periodicity in Properties' in NCERT's Class 11 Chemistry textbook. Nonetheless, as part of the council's "rationalisation" process, an entire chapter that introduces students to the concept has been omitted from NCERT's Class 10 Science textbook. However, the Class 11 chapter on the subject remains on the syllabus.
The NCERT made the deletion from Class 10 textbooks in June 2022, stating that "in light of the COVID-19 pandemic, it is imperative to reduce the content load on students." Last year, paragraphs on 'Evolution' were removed from the class 10 Science textbook, among other changes. Last year's deletions and updates to textbooks have finally been implemented.
'Evolution,' including the Darwinian theory of natural selection, remains part of the educational curriculum, with a complete chapter on the subject in NCERT's Class 12 Biology textbook. Chapters on Fibre and Fabrics in Classes 6, 7, and 8 are among the other topics that have been removed from Science textbooks.
In the context of charkha, the Class 6 chapter on the topic mentioned Mahatma Gandhi. "Charkha is another hand-operated spinning device." Mahatma Gandhi popularised the use of charkha as part of the Independence cause. "He encouraged people to wear clothes made of homespun yarn rather than imported cloth made in British mills," it stated.
Another notable omission is the chapter "Why do we fall ill" from the Class 9 Science textbook. Ironically, the chapter teaches students about viruses and airborne infections such as Covid-19, noting that the NCERT conducted the rationalisation process.
"Such pathogenic microbes can spread through the air." This happens as a result of the little droplets emitted by an infected person who sneezes or coughs. Someone nearby can breathe in these droplets, giving the bacteria a chance to establish a new infection. "Common colds, coronavirus disease (Covid-19), pneumonia, and tuberculosis are examples of such diseases spread through the air," read a paragraph in the text that was modified after the pandemic broke out.
However, the entire chapter was removed due to the necessity to minimise content load as a result of disruptions in learning caused by Covid-19. In addition to its in-house specialists, the NCERT has enlisted the help of 25 external experts selected from the faculties of Delhi University, ICHR, several Kendriya Vidyalayas, and private schools to carry out the rationalisation.
The NCERT cites as reasons for the deletions content that is "overlapping," "not relevant or outdated in the current context," "difficult," and "easily accessible to children and can be learned through self-learning or peer-learning."
