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AP Chapter 1. Matter and Measurement. Chemistry. Chemistry is the study of the properties and behavior of matter . Matter is the physical material of the universe and has mass and volume , and therefore density. Matter. Elements – composed of a single type of atom.
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AP Chapter 1 Matter and Measurement
Chemistry • Chemistry is the study of the properties and behavior of matter. • Matter is the physical material of the universe and has mass and volume, and therefore density.
Matter • Elements – composed of a single type of atom. • Molecules – 2 or more atoms combined chemically to make a substance.
States of Matter • Gas – no fixed shape or volume – it takes the shape of its container and is compressible. • Liquid – distinct volume, but no fixed or distinct shape. It takes the shape of its container. • Solid – definite shape and volume. It’s non-compressible.
Pure Substances • Pure substances can NOT be broken down by physical means. • Elements can’t be broken down further • Compounds – can ONLY be broken down by chemical means into their elements. • 2H2O → 2H2 + O2 (using electrolysis)
Mixtures • Multiple substances are involved in mixtures, each with its own properties. • Mixtures are separated by physical means based on the properties of the substances in the mixture. • Evaporation • Filtration • Sorting
Mixtures • Heterogeneous Mixtures • Different composition in different areas of the sample. • Homogeneous Mixtures • The same composition exists throughout the sample. • Can be liquid or solid
Physical and Chemical Changes • Physical Change – changes the physical appearance but not the composition. State changes are physical changes. • Chemical Changes – changes the composition of the substance and creates a new substance with new and different properties.
Accuracy and Precision • Accuracy – How close the measured values are to the accepted values. • Precision – How close the measured values are to each other.