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AQA Education, [1] trading as AQA (formerly the Assessment and Qualifications Alliance), is an awarding body in England, Wales and Northern Ireland. It compiles specifications and holds examinations in various subjects at GCSE, AS and A Level and offers vocational qualifications. AQA is a registered charity and independent of the government.
The A-level (Advanced Level) is a subject-based qualification conferred as part of the General Certificate of Education, as well as a school leaving qualification offered by the educational bodies in the United Kingdom and the educational authorities of British Crown dependencies to students completing secondary or pre-university education. [1]
The O grade was equivalent to a GCE Ordinary Level pass which indicated a performance equivalent to the lowest pass grade at Ordinary Level.. Over time, the validity of this system was questioned because, rather than reflecting a standard, norm referencing simply maintained a specific proportion of candidates at each grade, which in small cohorts was subject to statistical fluctuations in ...
In 2018, Edexcel introduced a new specification, meaning the Advanced Extension Award in mathematics would continue to be available to students in 2019 and beyond, as a qualification aimed at the top 10% of students at A level. [6]
In addition to specifications for each chemical, Reagent Chemicals provides detailed methods for determining how to measure the properties and impurities listed in the specifications. Included are detailed explanations for numerous common analytical methods such as gas , liquid , ion , and headspace chromatography , atomic absorption ...
Chemical formula Synonyms CAS number CAgO carbonylsilver: CCl 2 F 2: dichlorodifluoromethane freon-12: 75-71-8 CCl 4: carbon tetrachloride tetrachloromethane: 56-23-5 C(CN) 4: tetracyanomethane: 24331-09-7 CFCl 3: trichlorofluoromethane freon-11: 75-69-4 CFCl 2 CF 2 Cl: chlorotrifluoromethane freon-13: 75-72-9 CHCl 3: chloroform ...
Bis(trimethylsilyl)acetamide (BSA) is an organosilicon compound with the formula MeC(OSiMe 3)NSiMe 3 (Me = CH 3).It is a colorless liquid that is soluble in diverse organic solvents, but reacts rapidly with moisture and solvents containing OH and NH groups.
Skeletal structural formula of Vitamin B 12.Many organic molecules are too complicated to be specified by a molecular formula.. The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. [1]