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Chemistry 2A. Matter States of matter Physical and chemical changes Pure substances Mixtures: heterogeneous and homogeneous Elements and compounds Names and symbols of elements. States of Matter. States of Matter. Plasma.
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Chemistry 2A • Matter • States of matter • Physical and chemical changes • Pure substances • Mixtures: heterogeneous and homogeneous • Elements and compounds • Names and symbols of elements
Plasma • Plasmas are conductive assemblies of charged particles, neutrals and fields that exhibit collective effects. Further, plasmas carry electrical currents and generate magnetic fields.Plasmas are the most common form of matter, comprising more than 99% of the visible universe.
Physical PropertyBROMINE Br Liquid at room temperature Brown M.P. -70C B.P. 59 0C
Physical Property Sulfur Solid at room temperature Yellow M.P. 1130C B.P. 4450C
Physical changesConversion without causing change in composition
Chemical properties • Examples of chemical properties-Electronegativity-Reactivity against other chemical substances -Heat of combustion -Toxicity-Chemical stability in a given environment -Flammability-Capability to undergo a certain type of reaction -Preferred types of bonds to form, e.g. metallic, ionic, covalent
Homogenous mixtures look the same throughoutA single visible phases
Mixtures can be physically separated pure substances cannot be separated
Elements About 100 substances have resisted all attempts to split them into two or more stable components. These substances are known as elements
Elements Sulfur Magnesium metal
All other substances are composed of combinations of two or more elements. Compounds
elemental symbols • Each element has its own symbol • Consists of one or two letters • Only the first letter is capitalized • Often symbol is based on English name B = Boron, Ne=Neon Maybe based on Latin name Fe = iron (ferrous) Maybe based on German name W = Tungsten (wolfram)