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The textbooks are in color-print and are among the least expensive books in Indian book stores. [11] Textbooks created by private publishers are priced higher than those of NCERT. [ 11 ] According to a government policy decision in 2017, the NCERT will have the exclusive task of publishing central textbooks from 2018, and the role of CBSE will ...
In addition to the element's name, symbol, and atomic number, each element box has a drawing of one of the element's main human uses or natural occurrences. The table is color-coded to show the chemical groupings.
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Chemistry is the scientific study of the properties and behavior of matter. [1] It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances.
A set of periodic-table elements, lacking several highly radioactive elements which are impractical or impossible to collect. An assortment of precious metals Hafnium samples for collectors. Element collecting is the hobby of collecting the chemical elements. Many element collectors simply enjoy finding peculiar uses of chemical elements.
Description: This book explained Dalton's theory of atoms and its applications to chemistry. Importance: The book was one of the first to describe a modern atomic theory, a theory that lies at the basis of modern chemistry. [3]: 251 It is the first to introduce a table of atomic and molecular weights.
The elements in group 13 are also capable of forming stable compounds with the halogens, usually with the formula MX 3 (where M is a boron-group element and X is a halogen.) [14] Fluorine, the first halogen, is able to form stable compounds with every element that has been tested (except neon and helium), [15] and the boron group is no exception.
Most of the chemistry has been observed only for the first three members of the group (the chemistry of dubnium is not very established, but what is known appears to match expectations for a heavier congener of tantalum). All the elements of the group are reactive metals with a high melting points (1910 °C, 2477 °C, 3017 °C).