chemistry concepts. chemical: any substance that has a definite composition is dinitrotoluene a...
TRANSCRIPT
Chemical:
• Any substance that has a definite composition
• Is dinitrotoluene a chemical?
• Is water a chemical?
• Is salt a chemical?
States of matter:
• Solid:• Has a fixed volume and shape• Molecules are closely packed and vibrate (Brownian
motion)
• Liquid:• Has a definite volume, no fixed shape• Molecules spread apart and move past one another
• Gas:• Has no fixed volume. Will occupy any given area.• Molecules are far apart and move rapidly.
Physical property:
• Characteristics of a property, such as• State of matter• Mass• Volume• Density• Color• Odor• Taste• Temperature
• Melting point—solid to liquid
• Boiling point—liquid to gas
• Freezing point—liquid to solid
• Sublimation—solid to gas
• Viscosity • Viscous or runny
• Ductility and compressaibility
• Ductile=able to be stretched into thin wires•
Intensive property:
• Does NOT depend on amount of substance• Color
• Density
• Temperature
• Melting point, boiling point
Extensive property:
• Does depend on amount of substance• Mass
• Volume
• Heat capacity
Chemical properties• If and how a substance reacts with other
substances, such as• Oxygen• Water• Acid• Light• Combustability
Physical change:
• Change in state of matter
• Chemical properties stay the same
• No bonds are broken
Examples of physical changes:
• Change in state of matter• Evaporation• Vaporization• Dissolving• Melting
Chemical change
• Bonds are broken
• Substances change into new substances
• Original properties are changed or lost
Indicators that a chemical change (reaction) has occurred:
• New substances are formed:• New color
change• New gas is
produced• Odor produced• Precipitate—solid
that is produced when 2 liquids are mixed
• Energy is released:• Temperature
change• Light is given off• Sound produced• electricity