Chemistry Chapter 1 & 2 Introduction to Chemistry & Matter and Change

 Chemistry – study of matter and the changes it undergoes.

 Organic chemistry – chemistry of carbon compounds.

 Inorganic chemistry – chemistry of non-carbon compounds.

 Physical chemistry – defines chemical behavior mathematically.

 Analytical chemistry – identifying the composition of materials.

 Biochemistry – the chemistry in living organisms.

 Mass –the amount of matter in an object.  Matter – anything that has mass and takes up space (not energy).

 substance (pure) – has a fixed composition unlike a mixture; (i.e. element or compound)

 Physical property – what a substance looks like. (color, size, shape)

 Physical change – change in physical appearance. (chop, cut, paint)

 Change of state – a physical change of a substance from one state to another. Requires the addition or removal of heat. Changes of State Changes of State

 Solid – matter with definite shape and volume.

 Liquid – matter with indefinite shape and definite volume.

 Gas – matter with indefinite shape and volume.

Molecule animation

 Vapor –gaseous form of a substance that is normally a liquid or solid at room temperature.

 Plasma – atoms lose their electrons at a high temperature.

 Mixture – a physical blend of two or more substances.

 Heterogeneous mixture – not uniform.

 Homogeneous mixture – uniform mixture

 Solution – a homogeneous mixture. (ex. Salt water or kool-aid)

 phase – part of a system with uniform composition and properties. Ex. Oil and water are in two phases; in two phases; Ice water has two Ice water has two phases phases

 distillation – physical method of separation involving boiling, then condensing vapor.

 Atom – smallest unit of an element.  Element – a pure substance made of only one kind of atom.  Compound – two or more elements that are chemically bonded.

Mixtures vs Pure Substance Mixtures vs Pure Substance

 Chemical symbol –  represents an element  1 – 3 letters  the first letter is capitalized  Ex. Fe, Si (not SI!!!)

 Chemical property – a substance’s ability to undergo changes that transform it into different substances.  Ex. Flammable, reacts with water, etc.

 Chemical change (or chemical reaction) – Change in which one or more substances are changed into new substances.

 Reactants – substances that react in a chemical change. Go on the left of a chemical equation.  Products – substances that are formed in a chemical change. Go on the right of a chemical equation.

Reactants  Products Reactants  Products 2Na + Cl 2  2NaCl 2Na + Cl 2  2NaCl H 2 O  H 2 + O 2 H 2 O  H 2 + O 2 2Na + 2H 2 O  2NaOH + H 2 2Na + 2H 2 O  2NaOH + H 2 2K + 2H 2 O  2KOH + H 2 2K + 2H 2 O  2KOH + H 2

Indicators of a chemical change (5) Color change Odor change Production of a gas or a solid (precipitate) Energy change (heat, light, sound) Usually irreversible

Law of conservation of mass Mass is neither created nor destroyed Mass reactants = mass products 2Na + Cl 2 2NaCl (10g reactants) (10g products)