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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.
A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
JEE (Advanced) is conducted in two papers of three hours each – Paper-1 and Paper-2 (both compulsory) consist of questions from three major subjects: physics, chemistry and mathematics. Unlike most of the other exams, the type, the number of questions being asked in the paper, the total marks and the marking scheme varies from year to year ...
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound.It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [1]
The National Standard Examination in Chemistry or NSEC is an examination in chemistry for higher secondary school students in India, usually conducted in the end of November. [1] The examination is organized by the Indian Association of Chemistry Teachers. Over 30,000 students, mainly from Standard 12, sit for this examination.
Thus, on both descending a period and crossing a group by one element, the changes "cancel" each other out, and elements with similar properties which have similar chemistry are often found – the atomic radius, electronegativity, properties of compounds (and so forth) of the diagonal members are similar.
In organic chemistry, the Paal–Knorr synthesis is a reaction used to synthesize substituted furans, pyrroles, or thiophenes from 1,4-diketones.It is a synthetically valuable method for obtaining substituted furans and pyrroles, which are common structural components of many natural products.