States, Properties, Changes, and Conservation MATTER States, Properties, Changes, and Conservation

Matter Anything that has mass and volume

States of Matter

Changes in States of Matter Evaporation Condensation

Properties of Matter Physical Property – observed without changing the identity of the substance Density Color Melting point Chemical Property – cannot be observed without changing the identity of the substance Flammability

Changes in Matter Physical Changes – do not alter the identity of the substance Crushing Tearing Melting Chemical Changes – alter the identity of the substance Burning Rusting Cooking

Identifying Chemical Changes Color Change Heat production/ removal Gas formation Bubbles Change in smell/odor Precipitation

Conservation of Matter Law of Conservation of Mass – matter, like energy, is neither created nor destroyed in any process Lavoisier proved that total mass does not change during any chemical reaction

Elements, Compounds, and Mixtures

Elements An element is a substance that cannot be separated into simpler substances by a chemical change. Named after scientists, countries, states, planets Chemical symbols or abbreviations Periodic Table of ELEMENTS May be monoatomic, diatomic, or triatomic

Odd Abbreviations Au – gold Fe – iron Pb – lead Hg – mercury K – potassium Ag – silver Na – sodium Sn – tin W – tungsten

Compounds A compound is a substance that contains two or more elements. Rust is caused by a reaction between iron and oxygen to form iron oxide 4 Fe + 3 O2  2 Fe2O3

Distinguishing between Elements and Compounds Both are pure substances Unique chemical and physical properties Compounds = two or more different elements

Mixtures A mixture is a blend of two or more pure substances Heterogeneous – visibly different parts Homogeneous – no visibly different parts

Separation Techniques Filtration Distillation Crystallization Chromotography

Filtration

Distillation

Crystallization

Chromotography

Assignment Write an essay explaining the four methods of separation. Include the pros and cons of each method. Indicate for which type of mixtures each method is best.