Unit 1 – Matter and Energy Chapter 1- Matter and Change

What is Chemistry? Chemistry: the study of the composition, structure, and properties of matter, the process that matter undergoes, and the energy changes that accompany these processes. Chemicals: any substance with a definite composition.   Examples: H2O and H2O2  

Matter and Its Properties Atom: Smallest unit of an element…   Element: A pure substance that CANNOT be broken down into a simpler substance (one type of atom) Example: Cu or H2 Compound: A substance that can be broken down into a simpler substance (2 or more elements chemically bonded together) Example: H2O or H2SO4

BP, MP, Density, Conductivity Physical Property Measured without changing the substance Intensive DOES NOT depend on the amount Extensive DEPENDS on the amount BP, MP, Density, Conductivity Volume Mass Volume, Mass, Energy

Behavior of a substance interacting with another Chemical Property Behavior of a substance interacting with another Coal Burning Iron Rusting

Matter and Its Properties Physical Change: Chemical Change: Same substance present BEFORE and AFTER the change Produces ONE or MORE new substances.

Matter and Its Properties Indicators of Chemical Change Precipitate Gas Color change Change in energy Emission of light  

Classification of Matter

Classification Mixtures Pure substances Combination of two or more substances that retain their original properties Kool aid = Water + sugar +flavoring Pure substances Matter made of one substance Gold = 1 type of atom Orange = not pure because it’s made of more than one substance

Mixtures Homogeneous Heterogeneous No matter what portion you study it’s the same as the rest Sugar water Kool-aid Heterogeneous The porportions of materials change Orange juice Oil and water

Pure Substances Elements Compounds A material that cannot be broken down any further Found on the periodic table Gold, silver, oxygen Compounds 2 or more elements chemically bonded together Salt = NaCl Sugar = C6H12O6 Water = H2O

Elements Metals Location: left of stair step line. Properties: good conductor of heat and electricity, malleable, ductile, high tensile strength.   Nonmetals Location: right of stair step line. Properties: poor conductor of heat and electricity, brittle if solid, many are gases at room temp.

Elements continued Types of Elements Metalloids Location: along the stair step line Properties: have some characteristics of metals and nonmetals   Nobel Gases Location: group 18 Properties: generally nonreactive