Chemical & Physical Changes Created by: Mrs. Dube

Characteristic Properties Copy into notes! Physical properties describe a substance! Physical properties are the characteristics of a substance that can be observed without changing the identity of the substance. All of your senses can be used to detect physical properties.

Physical Properties (copy all) Color Shape Size Texture Volume Mass Density Boiling point Melting point Freezing point Solubility

Physical Properties Copy into notes! Physical properties of a substance are independent of the amount of the sample. (copy into notes) For example, the boiling point of water is 212°F or 100°C whether you have a gallon of water or a cup of water. Density of lead will always be 11,300 kg/m3 and the density of gold will always be 19,300 kg/m3

Physical Changes Copy into notes! After a physical change, the substance is still the same substance Changes in state are physical changes The substance may have some different properties after a physical change

Physical Changes Copy into notes! Physical changes in matter include: Cutting, tearing, folding Melting, boiling, freezing Evaporating Sublimating Changes in states of matter Creation of a mixture Creating solutions Breaking

Chemical Properties Copy into notes! Burning Rusting Corrosion Radiation Oxidation Flammability Reacts with water Reacts with air Reacts with acid

Reactants and Products Copy into notes! Reactants are the substances present at the beginning of a chemical reaction Products are the substances formed by a chemical reaction present at the end of a chemical reaction

Chemical Changes “aka” Chemical Reactions (Copy into notes!) Chemical changes are also known as chemical reactions A change that produces one or more new substances is a chemical change or a chemical reaction

Chemical Changes: Breaking down Water Electrolysis of water is an example of a chemical change that water undergoes Water is broken down into hydrogen and oxygen using an electric current to break the bonds

Chemical Reactions (Copy into notes) A chemical reaction produces new substances by changing the way in which the atoms are arranged New arrangements of atoms form different substances

Evidence of Chemical Reactions (Copy into notes) Color change Formation of a precipitate (a solid product) Formation of a gas (sometimes seen as bubbles) Temperature change Production of odor

Check for Understanding Restate the question in your answer in your notes! How do reactants differ from products? How can you tell that a chemical reaction has occurred?