Classification of Matter • Matter – anything with mass and volume
Phase Differences Solid – definite volume and shape; particles packed in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun.
Condense Freeze Evaporate Melt Gas Liquid Solid
Chemical vs. Physical Change Physical change – changes form, not composition - all changes in phase are physical Chemical change – change that produces a new substance(s) with different properties
Mixtures • Made up of two substances together but not bonded • Heterogeneous- mixture is not the same from place to place. • Homogeneous- same composition throughout (also called solutions)
Mixtures Can Be Separated by Physical changes • Distillation • Filtration • Chromotography
Pure Substances Compounds – substance with a constant composition - can be broken down into smaller elements be chemical processes Elements – substance that cannot be decomposed into simpler substances by chemical or physical means - composed of smallest component of matter (Atoms)
Chemical Changes can be Identified by Observation Change in color Change in temperature Formation of a gas Release of light Formation of a precipitate
Law of Conservation of Mass In any chemical or physical change – matter (and its mass) is neither created nor destroyed
Law of Definite Composition A given compound always contains the same proportion of elements by mass Example: Water has a mass ratio of hydrogen to oxygen of 1:8. What will the mass of oxygen be in a sample of water that contains 3g of hydrogen?
Law of Multiple Proportions When two elements form a series of compounds, the ratios of the masses of the second element that combine with 1g of the first element can always be reduced to small whole numbers