Search results
Results from the WOW.Com Content Network
A multiple choice question, with days of the week as potential answers. Multiple choice (MC), [1] objective response or MCQ(for multiple choice question) is a form of an objective assessment in which respondents are asked to select only the correct answer from the choices offered as a list.
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 traditional Balz–Schiemann reaction employs HBF 4 and involves isolation of the diazonium salt. Both aspects can be profitably modified. Other counterions have been used in place of tetrafluoroborates, such as hexafluorophosphates (PF 6 −) and hexafluoroantimonates (SbF 6 −) with improved yields for some substrates.
The United States National Chemistry Olympiad (or USNCO) is a contest held by the American Chemical Society (ACS) used to select the four-student team that represents the United States at the International Chemistry Olympiad (IChO). Each local ACS section selects 10 students (or more for larger ACS sections) to take the USNCO National Exam.
All India Secondary School Examination, commonly known as the class 10th board exam, is a centralized public examination that students in schools affiliated with the Central Board of Secondary Education, primarily in India but also in other Indian-patterned schools affiliated to the CBSE across the world, taken at the end of class 10.
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.
Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents.
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron.The bond angles are arccos(− 1 / 3 ) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane (CH 4) [1] [2] as well as its heavier analogues.