Properties of matter and applications

Physical Properties

Physical properties are any characteristic of a material that you can observe without changing the identity of the substance that make up the material. These are usually physical descriptions of the material, but they can also include some behaviors.

Physical descriptions Behaviors Color Shape Size (volume) Melting/Boiling Point Mass Weight Phase (solid, liquid, gas) Temperature Elasticity Density magnetic = attraction of a magnet to iron ductile = drawn into a wire like copper malleable = able to be pounded into sheets Viscosity Buoyancy

Fluids A FLUID is any material that has the ability to flow. This includes gases and liquids Physical property

D (g/ mL) Density m ___ = vol Is the amount of matter in a certain volume It is calculated by dividing the mass of the object (or material) by the volume m ___ (g) D (g/ mL) = vol (mL)

Viscosity Viscosity is the resistance of a fluid to flow. The “thicker” the fluid, the greater the viscosity. Determined by the size of the molecules and by their tendency to stick together (cohesiveness). Viscosity decreases as temperature increases. (If you heat something up, it is easier to pour)

Physical Properties can be used to separate materials

Sort by size, sifting or sorting Sunflower vs. Poppy Seeds

Sort by magnetism Iron vs. Sand

PHYSICAL CHANGE = a change in size, shape, or state of matter (ice  water  gas) Rip a piece of paper

May involve energy changes but NOT change the kind of substance Melt Iron  change color and shape, but still iron

Distillation = process of separating substances in a mixture by evaporating a liquid and recondensing its vapor. Liquid vaporizes and condenses, leaving the solid (salt) behind

Chemical Properties of matter and applications

CHEMICAL PROPERTIES = a characteristic of a substance that indicates whether it can undergo a certain chemical change. “Flammable” Burning produces new substances

Many medicines  dark bottles Change chemically if exposed to light

CHEMICAL CHANGE Rust = a change of one substance into another (Remember that if you are forming a new material it is most likely going to have a new appearance. This means That you will almost always see physical changes accompany a chemical change) Rust Smell of rotten egg

Foaming of antacid tablet

Only sure proof that a new substance is produced is a rapid release of energy – heat, light, and sound

Hydrogen gas combines with oxygen =Explosion rocket engine

 Chemical Change: Cleaning tarnished silver Tarnish is silver sulfides that form from sulfur compounds in the air 

Pot of water = baking soda and crumpled aluminum foil

 Change back to silver by chemical reaction

CHEMICAL CHANGE vs PHYSICAL CHANGE

Sunlight + Carbon Dioxide + Water  Chemical Equation Reactants  Products A chemical equation can be written for A process that has a chemical reaction Take In  Make/Give Off Sunlight + Carbon Dioxide + Water  Glucose (sugar) + Oxygen

6CO2 + 6H2O  C6H12O6 + 6O2 Light Light Energy CO2 + H2O Sugars + O2 Chloroplast Sugars + O2

Forces of nature reshape Earth’s surface WEATHERING – CHEMICAL OR PHYSICAL CHANGE? Forces of nature reshape Earth’s surface

Physical: Large rocks split when water freezes Doesn’t change the rock

Wood combustible and burnable = chemical property

Pile of ash is small – loss of matter? Collected = oxygen, smoke and gas that escaped = No mass lost

Law of Conservation of Mass = mass before chemical change equal mass after chemical change “Mass cannot be created nor destroyed”