chemical change


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chemical change

A process in which molecular bonds break or form to create substances with new properties or characteristics. For example, oxygen and hydrogen combine to form water. Sodium (a metal) and chlorine (a gas) combine to form sodium chloride, or common salt. Glucose (C6H10O5) is metabolized to carbon dioxide (CO2) and water (H2O). Oxygen combines with hemoglobin to form oxyhemoglobin when the hemoglobin in the blood comes into contact with the oxygen in the air contained in the alveoli of the lungs. A chemical change is also known as a chemical reaction.
References in periodicals archive ?
According to their explanations, it is a chemical change because the acid gets ionised and a new product is formed.
Previous studies of ninth- grade chemistry topics found that students can understand the course unit on physical and chemical changes (Ayas & Demirbas, 1997), but have difficulty understanding events at the micro level and explaining chemical changes in relation to chemical bonds (Mirzalar Kabapinar & Adik, 2005).
3) The majority opinion, not yet a consensus, is that the chemical change was caused by some sort of radiation impinging on the Shroud as it enclosed the dead body of The Man in the Shroud.
We will consider [M.sub.c] as the variable product reflecting chemical changes that occur during the aging process.
Together, these chemical changes create a high risk for gallstone formation.
Identify when a chemical change is taking place by observing a change in temperature, the appearance of new substances or the disappearance of an original substance; and
An enzyme is a protein that acts as a catalyst for a chemical change in the body - that is, it greatly speeds up the rate at which the chemical change occurs.
It showed that when the gene promoter is altered by a chemical change called methylation, patients respond better to treatment.
SMELTER--One who melts or fuses (as ore), often producing an accompanying chemical change usually to separate the metal.
As a part of a doctoral thesis considering the history of teaching physical and chemical change, 641 chemistry/science textbooks have currently been examined.
Here was an entire society that lived on chemical change involving neither light nor photosynthesis.