Chemistry Joke What do you call iron blowing in the wind? Febreeze!

“Matter and Change”

Chemistry - the study of matter and its changes Matter - anything that has mass and takes up space Air and smoke are examples of matter Light and heat are energy, not matter Mass - quantity of matter (numbers of atoms or molecules) Weight - measure of gravitational attraction Dependent on gravity of location

Study of Matter States of Matter Classifications of Matter Physical Properties of Matter Physical Changes of Matter Chemical Properties of Matter Chemical Changes of Matter

States of Matter – Particle Diagrams Gas - indefinite volume and shape Liquid - definite volume, indefinite shape Solid - definite volume and shape Plasma – a gas that has a charge because it has been heated and has lost its electrons.

Classifications of Matter plasma

Pure Substances Elements Compounds Simplest form of matter / building blocks Composed of only one type of atom Cannot be simplified Ex: Any element on periodic table Compounds Substances that can be separated only by chemical means into simpler substances Can be written as a chemical formula Ex: water, H2O; baking soda, NaHCO3; ammonia, NH3

Mixtures 2 Types Can be separated by physical means Homogeneous Composed of only one phase of matter Completely uniform throughout Also called a solution Ex: salt water, air Heterogeneous Non-uniform distribution Ex: apple, salad Can be separated by physical means Filtration, distillation, chromatography

Physical Separation of a Homogeneous Mixture by Distillation liquid alcohol and water alcohol

Physical Separation of a Heterogeneous Mixture Using Magnetism

Physical Separation of a Homogeneous Mixture Using Chromatography

Physical Properties of Matter Properties that can be observed and measured without changing the composition of the substance Color Solubility Electrical Conductivity State of Matter (solid, liquid, gas) Density Thermal Conductivity Melting and Boiling point Metallic Characteristics (malleability, ductility, & luster) Magnetic Properties

Physical Changes of Matter Changes in Form not Substance Phase changes are physical!! Melting, freezing, boiling, condensing, evaporating Tearing, breaking, cutting, crushing Dissolving is a physical change!!

Chemical Properties of Matter Ability of a substance to undergo a chemical reaction and form a new substance Flammability / Combustibility Acidic or basic Reactivity

Chemical Changes of Matter Indicators that a chemical change may have happened: Energy is absorbed or released (temperature changes) Color changes Gas is produced (bubbling, fizzing, or odor change; smoke) Precipitate is formed - a solid that separates from solution (won’t dissolve) Irreversibility - not easily undone

Words Associated with Chemical Change Burn Decompose Corrode Rot Ferment Cook Rust Explode -----------

Chemical Reactions of Matter Starting substances called reactants change to form products. Reactant + Reactant → Product

The Law of Conservation of Mass (of Matter!) In any physical or chemical change, mass is neither created nor destroyed; it is CONSERVED! In other words, the mass of the reactants will ALWAYS equal the mass of the products.

43.43 g Original mass = 43.43 g Final mass reactants → product

Chemistry Joke Q: H2O is water and H2O2 is hydrogen peroxide. What is H2O4? A: Drinking, Bathing, Etc.!