Physical Science WarmUp I have an object that is 5cm long by 6 cm wide by 2 cm tall. What is the density of this object if it has a mass of 30g? Will the object above sink or float in water? (Density of water is 1 g/cm³) ***ALL make-up work and/or missing assignments need to be completed by October 25th. This includes all missing tests and quizzes! No work will be accepted after this date.

Classifying Matter: Elements, Compounds, and Mixtures Physical & Chemical Properties and Changes

Atoms Elements Compounds Molecules Pure Substances A sample of matter that has definite chemical and physical properties. Atoms Elements Compounds Molecules

Elements pure substance that cannot be separated into simpler substance by physical or chemical means.

Compounds Pure substance composed of two or more different elements joined by chemical bonds. Made of elements in a specific ratio that is always the same Has a chemical formula Can only be separated by chemical means, not physically H2O NaCl CO2

Mixtures A combination of two or more pure substances that are not chemically combined. substances held together by physical forces, not chemical No chemical change takes place Each item retains its properties in the mixture They can be separated physically Chem4kids.com

2 types of Mixtures Homogeneous Heterogeneous Looks the same throughout Ex) milk, salt water Heterogeneous Can see separate layers or components Ex) Salsa, Salad

Properties of Matter 2 types Physical Properties Chemical Properties

Physical Properties & Changes Definition - a characteristic of a substance that can be observed or measured without changing the composition of the substance ex. viscosity, conductivity, malleability melting point, boiling point - remain the same for all pure substances ALL PHASE CHANGES ARE PHYSICAL! (Melting, Freezing, Boiling, Condensation, Sublimation, Evaporation, Deposition)

Chemical Properties & Changes Definition - any ability to produce a change in the composition of matter - can only be observed when the substances in a sample of matter are changing into a different substance Ex) Flammability, Reactivity

5 Clues of a Chemical Change Evidence of a chemical change - the production of a gas (bubbles) - the formation of a precipitate - the presence or absence of heat (hot or cold) - the emission of light - a color change during the reaction

Warm-Up (10/18) 1. What is the difference between an element, a compound, and a mixture? 2. What is the difference between a homogeneous mixture and a heterogeneous mixture? 3. What is the difference between a physical and a chemical change? ***Test on Density and sigfigs next time you have this class!!!

Liquids Crash Course Chemistry

Assignment 1. Finish physical and chemical changes worksheet from last class. 2. Complete the two worksheets at the front of the room. You may write on BOTH of these ***Keep all electronics away. Automatic referral if you do not.