Physical vs. Chemical What is the difference between a chemical change and a physical change? Students write anything underlined!

What’s the… MATTER?! Matter is: anything that has mass and takes up space. Everything is made up of matter. Everything in the universe is either matter or energy! Fire, lightning, sound, etc. = energy!

What’s the… MATTER?! We can tell different types of matter from one another by their characteristics (also called properties) The two types of properties are: Physical Chemical

Law of conservation of Mass: Matter is never created, nor destroyed, only changed. The mass you start with is equal to the mass when you are done.

Physical Properties Properties that describe the physical characteristics of a substance and not how the substance behaves chemically.

Examples of Physical Properties ARE: Color Shape Size Texture Mass, volume, density State (solid, liquid, gas)

PHYSICAL PROPERTIES SPECIFIC TO METALS: Malleability: can be hammered into sheets. Conductivity: heat and electricity can move through it easily. Sonorous: makes a bell-like sound when it is hit. Ductile: can be pulled into wires (like the ones in your headphones). Magnetism – is it magnetic? Discuss examples of each (desk is made of sheets of metal, coin vs pencil for sonorous)

Physical changes: Are changes to the appearance without changing a substance’s identity. Identity = People have different looks/behaviors (compare characteristics of two kids). Identity is expressed in clothes they wear and things they say. Just as elements on PT have their own identities.

Physical Change Changes in states of matter: Energy added or taken away will cause the matter to vibrate faster or slower. Slowest moving matter is classified as a solid. Fastest moving matter is classified as a gas. There are more like 20-30 states of matter that scientists have discovered, but you only need to know three!

What to look for in a physical change? Melting Freezing Condensing Vaporization

Other examples of physical changes… Dissolving Cutting Ripping Stretching Changing color with dyes. Breaking/ smashing Set up demo dissolving with a beaker of water and salt while reading. Get out putty in desk. Food die and water. It looks different, but nothing new was created.

Physical changes NON-EXAMPLES Create anything new Destroy or create matter Burning, baking, frying, heat in general, reactions to acid, fire, oxygen, water, light, electricity or radiation. Why are you all writing this…? Everything a physical change is not describes a chemical change (except bullet 2…that describes nothing cause we can’t do it!)

Chemical Properties A characteristic of a specific type of matter, like gold, that describes its ability to change into something new and different when it reacts to another substance.

Chemical changes Observations that DO change the identity of the object making a NEW substance

Chemical changes INCLUDE: Flammability Reacts with oxygen Reacts with acids, bases Reacts in the presence of electricity, heat, light Reacts to water, etc. IF A KID ASKS: Mostly black colored paperback book on shelf describes difference between acids and bases on 3rd grade terms (they both break things down, but how they break it down is better). Also good for water quality.

Chemical Change Produces a NEW substance with different properties other than the original substance The process of a chemical change is a chemical reaction

What to look for in a chemical reaction? Bubbles, fizzes, changes color (not dye) Taste change – cooking, burning, or spoiling food Odor change – smoke, fumes Changes in temperature – hot/cold Creation of a precipitate – when you mix two liquids and get a liquid and a solid. Creation of light Color change without the use of dyes

Creation of a Precipitate https://www.youtube.com/watch?v=2EQznGPZY5A

Chemical Changes in Temperature https://www.youtube.com/watch?v=GQkJI-Nq3Os Before video say: We aren’t talking about a microwave or refrigerator – they physically change the temperature.

Chemical Changes cannot… Be undone or reversed. Destroy or create matter. Non-examples: Breaking, cutting, ripping, tearing, color with dyes…

FYI When a chemical change happens, it usually also changes some of the physical properties as well Example: When I burn paper, that is a chemical change. The paper is reacting to the fire. It creates something new: ash and carbon dioxide gas! Ash and gas look, smell, and feel totally different than the paper you are currently writing on.

Try this…. See if you can identify which of the following are physical changes, or chemical changes? https://www.youtube.com/watch?v=0KFAoqODZok

What are we learning about? https://www.youtube.com/watch?v=uJOGy0dgmUU

Bingo Review! Physical Change Physical Property Law of Conservation of (LoCM) Matter Chemical Properties Chemical Change Texture Density Malleability Conductivity Sonorous Ductile Magnetic Dissolving Cutting Stretching Using Dyes Breaking Flammability Baking Reacting New Substance Bubbles/Fizzing Odor Change Forms a Precipitate