1. Atoms Review

2. Size of Atoms Remember our zoom in on Atoms? How small are atoms? What are Atoms?

3. Elements What is the definition of an element? What are some examples of elements?

4. Scientific Shorthand ElementSymbol AluminunAl IronFe GoldAu MercuryHg OxygenO ChlorineCl

5. Why the weird Short hand? Silver is argentum in Latin - hence Ag Gold is aurum in Latin - hence Au Potassium is named after the Latin word for “alkali” kalium - hence K. Potassium is one of the alkali metals Mercury’s former name was “hydrargyrum” from the Greek words for water and silver – Hg Sodium from the Latin natrium - hence Na Iron from the Latin ferrum - hence Fe

6. Why use Chemical Symbols? ● Easier to write H v. Hydrogen, or H2O for dihydrogen oxide ● Used worldwide Scientists regardless of language use chemical symbols

7. Parts of Atoms Where is the nucleus and Electron Cloud? Which particles are protons? Electrons? Neutrons?

8. What Makes up an Atom? Nucleus - small positively charged center of an atom. Protons - particles with a charge of 1+ Neutrons - particles with no electrical charge Electrons - particles with a charge of 1- Atoms of different elements differ in the number of protons they contain

9. Reading the Periodic Table If the atomic number is 7, how protons are there? How many electrons? If the atomic mass is 14.95, how many neutrons are there?

10. Using the Period table Practice Turn to the periodic table in your planner (R-13), and find out how many protons, neutrons, and elections are in each of these elements. Na S Ar Ti Be In N Br

11. molecules What is the definition of a Molecule? What are some examples ?

12. All Compounds are molecules!! What is the definition of a compound? Examples?

13. Why Do we have different States of Matter? What are the states of matter like?

14. STATES OF MATTER SOLID LIQUID GAS PLASMA Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide past each other Well separated with no regular arrangement. Vibrate and move freely at high speeds Has no definite volume or shape and is composed of electrical charged particles

15. History of atoms What are some discoveries scientists have made about atoms since Democritus?

16. Quantum Mechanical Model

17. Composition of Matter Notes

18. Materials are made of a pure substance or a mixture of substances. A pure substance, or simply a substance, is a type of matter with a fixed composition. A substance can be either an element or a compound. Pure Substances 1 1

19. All substances are built from atoms. If all the atoms in a substance have the same identity, that substance is an element. The graphite in your pencil point and the copper coating of most pennies are examples of elements. Elements Composition of Matter 1 1

20. Can you imagine yourself putting something made from a slivery metal and a greenish- yellow, poisonous gas on your food? Compounds Composition of Matter 1 1

21. Table salt is a chemical compound that fits this description. Even though it looks like white crystals and adds flavor to food, its components—sodium and chlorine—are neither white nor salty. Compounds Composition of Matter 1 1

22. Mixtures A mixture is a combination of two or more substances, where these substances are not bonded (or joined) to each other and no chemical reaction occurs between the substances.

23. Mixtures: Example of sand mixed with water are not in a fixed ratio It doesn't matter whether you add 20 g, 40 g, 100 g or any other mass of sand to the water; it will still be called a mixture of sand and water. keep their physical properties Neither of these substances has changed in any way when they are mixed together. The sand is still sand and the water is still water. can be separated by mechanical means There is no chemical process involved to separate. It is possible to separate the mixture by simply pouring the water through a filter. Something physical is done to the mixture, rather than something chemical.

24. A mixture, such as the pizza or soft drink shown, is a material made up of two or more substances that can be easily separated by physical means. Mixtures Composition of Matter 1 1

25. Unlike compounds, mixtures do not always contain the same proportions of the substances that make them up. (not always 3 to 1, it depends on how much you added) Mixtures are separated into two main kinds by particle size. Heterogeneous mixtures have particles that are large enough to be seen, and Homogeneous mixtures have particles that are too small to distinguish.

26. Heterogeneous Mixtures Composition of Matter A mixture in which different materials can be distinguished easily is called a heterogeneous mixture. 1 1

27. Most of the substances you come in contact with every day are heterogeneous mixtures. Some components are easy to see, like the ingredients in pizza. Heterogeneous Mixtures Composition of Matter 1 1

28. Heterogeneous mixtures can be further subdivided according to whether it is two liquids mixed, a solid and a liquid or a liquid and a gas or even a gas and a solid. These mixtures are given special names which you can see in table below. Phases of matterName of mixtureExample liquid-liquidemulsionoil in water solid-liquidsuspensionmuddy water gas-liquidaerosolfizzy drinks gas-solidsmokesmog

29. Soft drinks contain water, sugar, flavoring, coloring, and carbon dioxide gas. Homogeneous Mixtures Composition of Matter Soft drinks in sealed bottles are examples of homogeneous mixtures. The individual components can’t be seen. 1 1

30. Another name for homogeneous mixtures like a cold soft drink is solution. Homogeneous Mixtures Composition of Matter A solution is a homogeneous mixture of particles so small that they cannot be seen with a microscope and will never settle to the bottom of their container. Solutions remain constantly and uniformly mixed 1 1

31. Breakdown of Matter Matter Pure Substances Mixtures Element Compound Heterogeneous Mixture Homogeneous Mixture

32. Homogeneous Mixtures What is a homogeneous mixture? A mixture that is the same throughout. Examples: ● sugar & water ● saltwater ● lemonade from a mix Why do you think most homogeneous mixtures involve liquids?

33. Heterogenous Mixtures What is a heterogenous mixture? A mixture that does not mix evenly together. Examples: Trail Mix Italian Dressing Sand Soil

34. Suspensions What is a suspension? A suspension is when the particles of one substance are temporarily mixed in another substance.

35. Other Homogeneous Mixtures Colliod- a homogeneous mixture with particles that are large enough that they scatter light, but are evenly distributed. Tyndall effect- solutions allow light to pass through them, but the larger particles in a colloid scatter light.

36. Alloys Interesting Fact: An alloy is a homogeneous mixture of two or more elements, at least one of which is a metal, where the resulting material has metallic properties. For example steel is an alloy made up mainly from iron with a small amount of carbon (to make it harder), manganese (to make it strong) and chromium (to prevent rusting).

37. Quick Practice SubstanceMixture or PureHomogeneous or Heterogeneous Soda Steel Oxygen Iron filings smoke Limestone (CaCO3)

38. Key Concepts Every sample of a given substance has the same properties because a substance has a fixed, uniform composition An element has a fixed composition because it contains only one type of atom A compound always contains two or more elements joined in a fixed proportion The properties of a mixture can vary because the composition of a mixture is not fixed

40. Methods for Separating Mixtures Chromatography Decantation Filtration Distillation Evaporation

41. Decantation ● Decantation: A process that separates materials based on differences in density. Less dense materials are decanted, or poured off. ● Ex: Panning for Gold, pouring off the fat to make gravy, centrifuging blood to separate hematocrit from plasma

42. Chromatography Chromatography: A process that separates materials based by how quickly they move through another substance. Ex. Color chromatography for studying dyes, gel electrophoresis for studying genetic material

43. Filtration ● Filtration: A process that separates materials based on the size of particles ● Ex. Draining pasta, filtering coffee or tea

44. Evaporation ● Evaporation: A process used to isolate a solid dissolved in a liquid ● There will only be one substance left! ● Ex. Solar evaporation in Great Salt lake

45. Distillation ● Distillation: A process that separates the substances in a solution based on their boiling points ● Ex: distilling oils from plants