Today’s Date: 11/14/2016 PLEASE NOTE: Question of the Day!: Directions: Come in and make sure you grab all papers from the front cart. Get started on your Question of the Day (QOD) as soon as you enter! PLEASE NOTE: Have your notebook out! Question of the Day!: List the symbol for the first 10 elements on the Periodic Table. (Use the table on the wall as a resource!) Don’t forget about your mood meter! Class Agenda Answer QOD Physical and Chemical Properties and Changes Review Notes Pre-Lab – DUE THURSDAY! Drawing Atoms Practice

Chemical and Physical Changes And a review of chemical and physical properties

Examples of Physical Changes: Includes changes in shape or size: crumpling a sheet of paper melting an ice cube casting silver in a mold to make a ring breaking a bottle Flattening a penny @ the space needle Grinding coffee Includes Phase Changes: “melting, boiling, freezing, sublimation, condensation, deposition”

Physical Change: changes in the state or form of a substance but NOT a change in the chemical composition. The same element or molecules are present before and after. i.e.- melting gold coins into gold bricks

Physical Changes

Lets looks at different physical properties…

Physical Properties of matter These are the physical characteristics you can observe without change the chemical composition of the substance: Appearance/ Color/ Odor Texture/ hardness/ Luster (shiny) Density Melting point/ Boiling point (4 more to go...)

Physical Properties of matter continued Magnetism (yes or no) Solubility = the ability to dissolve in water Electrical conductivity = the ability to transport an electrical charge Malleability= how easily something can bend or be shaped

Energy and Physical Changes Physical changes are concerned with energy and states of matter. Adding or removing energy from a substance can change its physical make up or the state of the matter It takes energy to do physical changes like crushing a can.

Examples of Chemical Changes Running a car on gasoline Digesting food A rotten log degrading into soil Burning wood Reactivity = reacts with acid or base When things “rust, corrode, tarnish, rot, burn”

Let’s Talk about Chemical Changes Chemical Change: a change that converts the chemical composition of a substance into different chemical substances with different chemical make up. (The atoms will rearrange) i.e.- plants doing photosynthesis- turning water, CO2, and light into O2 and sugars

Big Hint for Chemical Change = You will not have the same stuff at the end, and you can’t go back to what you started with At least not without another reaction

Chemical Changes

Chemical changes we have (hopefully) seen before… Burning a candle is an example of a combustion reaction (Wax + O2  CO2 + H2O + heat energy) More chemical changes to come… Cooking often a chemical change because you can’t go back to the original form of the food (Fried egg)

Combustion reaction (chemical change example) Organic matter (like wood, cotton, or paper ) is made up of Carbon, Hydrogen, and Oxygen. When organic matter burns Organic molecules + O2  CO2 + H2O + HEAT energy (Carbon Hydrogen, Oxygen) Carbon Dioxide + Water (REACTANTS)  (PRODUCTS) Click to make this go away!

Chemical Properties of matter Chemical properties of matter describe its potential to undergo some kind of chemical change or reaction because of what it is composed of: Reacts with acid Potential to ignite or burn (flammable), light Produce a gas or precipitate Alcohol fermentation – like making wine or beer Chemical changes in color because of new product

Energy and Chemical Changes Energy may be needed to make the chemical reaction occur energy going into the system Like lighting a match or fireworks Other?? Energy may be a result of the reaction energy coming out of the system Exothermic = (“out” “heat”) Heat released Warm/hot to the touch Example? Endothermic= heat is lost or removed (“heat loss”) – cold to the touch

What other physical properties does he describe that were not on this presentation? What evidence can you look for to show there has been a chemical change? Give 4 examples from the video. Are they demonstrating a physical or chemical change? How do you know?

Structure of Water

Pre-Lab! Do it! All questions need to be 100% correct before you can start your lab on Thursday! There is a front and a back side! DONE?! Work on Elements, Compounds, Mixtures Review! (You might need a text book)