CHEM 103 Lecture Notes - Lecture 1: Chemical Substance, Chemical Change
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Ex: which of the following samples can be described as an element? (a) . Explanation: in this instance different colors represent different elements. if there are more than one color/ element, such as in a and b, it is no longer a singular element as the question asks for. Ex: which of the following samples can be described as a molecule? (a) . Explanation: for a substance to be considered a molecule it must have at least two atoms as do. Physical vs. chemical changes: physical change: no bonds are rearranged, chemical change: atoms are rearranged that result in a change of the chemical properties or chemical composition of the substance which results in a new substance(s) Ex: which of the following represents a chemical change? (a) (b) Explanation: b is correct because bonds are created to form the new chemical while in diagram.
