Physical and Chemical

Physical and Chemical

Physical Properties

• Properties that are used to observe or describe a specific type of matter.– Texture, color, luster, odor, solubility, polarity,

boiling point, density, melting point!

Chemical Properties

• The potential of a specific substance to undergo a chemical reaction (eg…stability and likeliness to change!)– Location on the periodic table can help us predict

the chemical properties of an element!• Which elements are very reactive (unstable)?• Which elements are not reactive (stable)?

Is this a physical or chemical property?

• Oil floats on top of vinegar in a salad dressing mixture.

• When the metal on a bike is left outside it rusts easily.

• Distillation works because alcohol boils at a lower temperature than water.

• Cleaning products with ammonia have a distinct smell.

Changes in matter

• The appearance of matter can change.

• Physical changes: change the appearance of matter without altering its chemical composition.

• Chemical changes: change in the appearance of matter that leads to a change in chemical composition.

Examples

Physical ChangeSublimation of dry ice

Chemical ChangeOxidation of copper on the Statue of Liberty

The cycling of materials through our environment involves both physical and chemical changes.

• What type of changes occur in the water cycle?

• What type of changes occur in the carbon cycle?

• How are humans disrupting these cycles?

Water Cycle

Carbon Cycle

Themes:

• Which chemical theme connects best to what we learned today? Why?

• What other theme(s) might apply? How might they relate?

Bunsen Burner Safety

• Always make sure gas jets are off until you are ready.

• Keep hair pulled back.• Check tube for leaks and secure to burner. Do

not touch burner once its hot!• If burn gets out of control, turn the gas jet off

and it will go out!!!

Physical Chemical Changes Lab

Goals:

1) Practice using a Bunsen burner.2) Identify reactions as either physical or

chemical changes.3) Develop a list of “clues” about whether

something is a chemical change!