1. Pure Substances Every sample of a given substance has the same properties because a substance has a fixed, uniform composition.
2. Elements and Compounds An element has a fixed composition because it contains only one type of atom. One capital letter A compound always contains two to more elements joined in a fixed proportion. More than one capital letter
3. The properties of a mixture can varyMixtures because the composition of a mixture is not fixed. Heterogeneous Homogeneous Comes from the Greek One mixture so thoroughly words: dissolved in another mixture that it is hard to distinguish between the two Hetero: Different: in the mixture. Geneous: Kind Ex: salt water.
4. Colloids Suspensions, Solutions,Based on the size of its largestparticles, a mixture can be classified as asolution, a suspension, or a colloid. Solution A homogeneous mixture that does not separate into layers over time Can be seen through Must be separated chemically
5. Colloids Suspensions, Solutions,Based on the size of its largestparticles, a mixture can be classified as asolution, a suspension, or a colloid. Suspension A heterogeneous mixture that separates into layers Can be separated physically
6. Colloids Suspensions, Solutions,Based on the size of its largest particles,a mixture can be classified as a solution,a suspension, or a colloid. Colloid Particles in between solutions and suspensions. Do not separate into layers Cannot be separated by a filter
7. Lava with high Lava with lowviscosity viscosity Viscosity • The thickness of a liquid • The higher viscosity, the thicker the liquid.
8. Separation techniques Distillation A process that separates a solution based on boiling points
9. Separation techniques Filtration A process that separates materials based on the size of their particles and/or solubility.
10. Separation techniques Evaporation A process used to isolate a solid dissolved in a liquid, Property: solubility
11. Flammability Flammability is a material’s ability to burn in the presence of oxygen. The ability to burn is not a physical property because you cannot observe burning without changing the composition of the of the material that is burning.
12. Reactivity Reactivity is the property thatdescribes how readily a substancecombines chemically with othersubstances.
13. Chemical and PhysicalChanges
14. Precipitates Any solid that forms and separates from a liquid mixture is called a precipitate.