Chemistry Review
Chemistry Review
Atoms/Elements/Molecules
• What is the difference between an atom and an element?
• What is the difference between an element and a compound/molecule?
• What is an example of an element?
Matter
• What are the 3 states of matter?• SOLID, LIQUID, GAS• Animation
Phase Changes
SOLID LIQUID GAS
Properties
• What is a property?• Describes, talks about it’s ability to…• Can be physical or chemical• Physical property: characteristic/ability of a
substance without changing it to something new• Chemical property: characteristic of a substance
that does has the ability to turn into something new
Physical & Chemical Characteristics
PHYSICAL CHEMICALChanges its appearance physically
Changes what it is made up of (can change the atoms to make a new thing); reacts
Examples of Properties
• Front Desk:PHYSICAL PROPERTIES CHEMICAL PROPERTIES
Color FlammableHardness Could change color if burnedAbility to breakMelting point of plasticNot flexibleNot magneticTexture
9/11 – notes stop here
9/17 Notes start Changes
• When it actually changes• Physical: changes size, shape, color but its still
the same thing• Chemical: changes what it completely is,
chemical reactions
Examples of changes
• Tearing paper• Burning paper• Breaking wood• Campfire• Mixing kool aid• Cooking a cake
Physical change
Physical change
Physical change
Chemical change
Chemical change
Chemical change
Property vs. Change
• Property = description or could change in the future• Change = change• 5 evidences of a chemical change• PCOGT – “Pirates can obtain great treasures”– Precipitate (solid forms)– Color change– Odor(smell)– Gas forms– Temperature change– Evidence of a chemical change– http://resources.educ.queensu.ca/science/main/concept/gen/g09/N.%20Sabet/precipitation.jpg
Property or Change?
• Boiling point• 2 different liquids mix bubbles• Food coloring in water• Burning an egg• It has a yellow color• It produced a smell
Property
Property
Property
Change
Change
Change
• Which of the following is an example of a chemical property of water?– A. Boils at 100 C– B. Is transparent– C. Has no odor– D. Reacts with calcium
Is it still water (H2O)
Transparent = see through/clear
No smell
Reacts = chemical reaction
• Which of the following is an example of a physical property of hydrogen? It
• A. Is less dense than air• B. Reacts with oxygen• C. Is highly flammable• D. Forms hydrochloric acid
PHYSICAL PROPERTY
Energy that can be given off in a chemical reaction
• 3 different kinds• Substance gets warmer?• HEAT ENERGY• Changes color?• LIGHT ENERGY• Creates a noise?• SOUND ENERGY
Common Chemical reactions
• Respiration• Rust• Photosynthesis• Combustion: 2 chemicals burning
How can you speed up a chemical reaction?
• Add heat• Stir• Crush
Don’t freak out
• Take your time• Use tools• Read the entire question• Look at the graphs and tables