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BBC Bitesize, [1] also abbreviated to Bitesize, is the BBC's free online study support resource for school-age people in the United Kingdom. It is designed to aid people in both schoolwork and, for older people, exams .
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.
The following outline acts as an overview of and topical guide to chemistry: . Chemistry is the science of atomic matter (matter that is composed of chemical elements), especially its chemical reactions, but also including its properties, structure, composition, behavior, and changes as they relate to the chemical reactions.
Triple Award Science, commonly referred to as Triple Science, results in three separate GCSEs in Biology, Chemistry and Physics and provide the broadest coverage of the main three science subjects. The qualifications are offered by the five main awarding bodies in England; AQA , Edexcel , OCR , CIE and Eduqas .
The 10 to 1 ratio was an estimate made in 1972; current estimates put the ratio at either 3 to 1 or 1.3 to 1. [301] The total length of capillaries in the human body is not 100,000 km. That figure comes from a 1929 book by August Krogh, who used an unrealistically large model person and an inaccurately high density of capillaries.
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.
Aluminum warrants special mention because it is the most abundant metal and the third most abundant element in the Earth's crust; [3] despite this, it is not essential for life. With this sole exception, the eight most highly abundant elements in the Earth's crust, making up over 90% of the crustal mass, [3] are also essential for life.
After cellulose, lignin is the second most abundant biopolymer and is one of the primary structural components of most plants. It contains subunits derived from p -coumaryl alcohol , coniferyl alcohol , and sinapyl alcohol , [ 15 ] and is unusual among biomolecules in that it is racemic .