What is meant by the term composition in chemistry [closed]








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This may seem trivial at first glance, but It is used a lot in introduction to chemistry chapters and so I need to understand what they mean by composition.


Yes, I have seen the google definitions, I am here because I dint understand them.


And lastly, is **chemical composition** the same as **composition**




Composition tells you what components something is made of.


Chemical composition tells you what type of atoms a compound is made of, and how many atoms of each type are in the compound. It is the information contained in a sum formula, for example of the molecule $\ce{H2O}$ (two atom of hydrogen, one atom of oxygen).


In biochemistry, the composition of a protein refers the which amino acids it contains, and how many of each. Similarly, you can discuss the composition of other polymers.


Sometimes, composition does not give you the number of components but only the ratio. For example, I could say a sample of DNA is composed of 56% A and T nucleotides, and 44% C and G nucleotides. Or I could say magnesium chloride crystals contain twice as many chlorine atoms than magnesium atoms, so we write $\ce{MgCl2}$. That makes sense because crystalline magnesium chloride is not made of molecules.


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