Chemistry Chapter 2

1. Chemistry Chapter 2 Matter and Change

2. Chemistry is… • …the study of the composition, structure, and properties of matter and the changes it undergoes C2H5OH+3O2 2 CO2 + 3 H2O + Energy Reactants  Products

3. Matter • Anything that has mass and occupies space. • The “stuff” we are made up of. • Mass • A measure of the amount of matter. • How much “stuff” is there.

4. Atom • The smallest unit of an element that maintains • the properties of that element Element • -A pure substance made of only one kind of atom • -There are 115 elements on the periodic table. • -88 occur naturally.

5. Compound • A substance that is made from the atoms of two or more elements that are chemically bonded. Example -Sucrose – C12H22O11 Sucrose is also known as table sugar, and is used to make Gummy Bears!

6. Properties of Matter • Extensive Properties - depend on the amount of matter that is present. • Examples - Volume, Mass, Energy Content (think calories!) • Intensive Properties - Do not depend on the amount of matter present. • Examples – Melting point, Boiling Point,Density

7. Properties of Matter • Physical Properties – Characteristics that can change without becoming a different substance • Examples – odor, color, physical state • Chemical Properties – its ability to form a new substance. • Examples – Wood burning, Rusting of steel, Digestion of food

8. Chemical Change A change in which one or more substances are converted into different substances. This is on an atomic level. Heat and light are often evidence of a chemical change.

9. Physical Change A change in a substance that does not involve a change in the identity of the substance. Example: Phase Changes

10. Mixtures Anything substance with a variable composition. EX. Wood Soda Coffee air Pure Substance -contains only a single element or compound EX. Gold ring distilled water NOT EXAMPLES: water from the tap, soda

11. Homogeneous Mixtures -same through out EX. Sea water, plastic cup Heterogeneous Mixtures -has areas with different properties EX. Wood, bucket of sand and water

12. Classification of Matter

13. States of Matter • Matter can take forms/states • What are they?

14. How do solids behave? • The particles of a solid are very tightly packed and move slightly (vibrate). • Definite shape • Definite Volume

15. How do liquids behave? • Particles in a liquid can slide past each other • Indefinite shape – takes shape of container • Definite volume

16. How do gases behave? • Particles in a gas can move about freely • Indefinite shape • Indefinite volume

17. How does plasma behave? • Particles in plasma are broken (charged particles) • Indefinite shape • Indefinite volume • Conduct electricity

18. Phase Differences Solid – definite volume and shape; particles packed in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun.

19. Copper Phases - Solid

20. Copper Phases - Liquid

21. Copper Phases – Vapor (gas)

22. States of Matter Graphic Organizer! For each of the states of Matter complete this information: • State • Definition • Proximity (how close the particles are to eachother) • Movement of the particles • Three examples

24. Properties of Metals • Metals are good conductors of heat and electricity • Metals are malleable (can be hammered into thin sheets) • Metals are ductile (can be pulled into wires) • Metals have luster (shiny)

25. Examples of Metals Potassium, K reacts with water and must be stored in kerosene or oil Copper, Cu, is a relatively soft metal, and a very good electrical conductor. Zinc, Zn, is more stable than potassium Mercury, Hg, is the only metal that exists as a liquid at room temperature

26. Propertiesof Nonmetals Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. • Nonmetals are poor conductors of heat and electricity • Nonmetals tend to be brittle • Nonmetals do not have luster • Many nonmetals are gases at room temperature

27. Examples of Nonmetals Microspheres of phosphorus, P, a reactive nonmetal Sulfur, S, was once known as “brimstone” Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

28. Properties of Metalloids Metalloids straddle the border between metals and nonmetals on the periodic table. • They have properties of both metals and nonmetals. • Metalloids are more brittle than metals, less brittle than most nonmetallic solids • Metalloids are semiconductors of electricity • Some metalloids possess metallic luster

29. Silicon, Si – A Metalloid • Silicon has metallic luster • Silicon is brittle like a nonmetal • Silicon is a semiconductor of electricity Other metalloids include: • Boron, B • Germanium, Ge • Arsenic, As • Antimony, Sb • Tellurium, Te

30. Period The Periodic Table Group or Family Group or family Period

31. Describe how to read the periodic table: • Every table has:

32. Describe how to read the periodic table: Atomic Symbol: • One or two letters chosen to represent an element. • These symbols are used every where in the world • Usually, abbreviation of the element or the abbreviated Latin name of the element.

33. Describe how to read the periodic table: Atomic Number The number of protons in an atom identifies the element. 

34. Describe how to read the periodic table: Atomic Mass: • The average mass of an element • Measured in atomic mass units ("amu”) • Is an average of all the isotopes of an element. Mass Number: • protons + neutrons = Mass Number • Is always a whole number.

35. Atomic Structure

36. What are the 3 major parts of an atom? • Proton • Neutron • Electron

37. The Nucleus • The central part of an atom • Composed of protons and neutrons • Contains most of an atom's mass • Discovered by Ernest Rutherford in 1911.

38. Protons • Positively charged particles found in the atomic nucleus. • Have a mass of 1 AMU • Are made from other particles called quarks.

39. Neutrons • Uncharged particles found in the atomic nucleus • Have a mass of 1 AMU • Made from other particles called quarks.

40. Electron • Negatively charged particles that surround the atom's nucleus. • Have no mass?? • Determine properties of the atom. • Chemical reactions involve sharing or exchanging electrons.

41. Draw a Diagram of an Atom

42. A diagram showing the location of each part of the atom.

43. Atomic Symbols • Some show the mass number and atomic number in nuclear symbol form mass number 23 Na atomic number 11

44. Isotopes • Atoms that have the same number of protons but different numbers of neutrons

45. Describe Isotope Example: http://education.jlab.org/glossary/isotope.html

46. Naturally occurring carbon consists of three isotopes, 12C, 13C, and 14C. State the number of protons, neutrons, and electrons in each of these carbon atoms. 12C 13C 14C 6 6 6 #p+ _______ _______ _______ #no _______ _______ _______ #e- _______ _______ _______

47. Answers 12C 13C 14C 6 6 6 #p+666 #no678 #e- 6 66

48. Some quick questions An atom has 14 protons and 20 neutrons. A. Its atomic number is 1) 14 2) 16 3) 34 B. Its mass number is 1) 14 2) 16 3) 34 C. The element is 1) Si 2) Ca 3) Se D. Another isotope of this element is 1) 34X 2) 34X 3) 36X 16 14 14

49. IONS • IONSare atoms or groups of atoms with a positive or negative charge. • Taking away an electron from an atom gives a CATION with a positive charge • Adding an electron to an atom gives an ANION with a negative charge. • To tell the difference between an atom and an ion, look to see if there is a charge in the superscript! Examples: Na+ Ca+2 I- O-2

50. PREDICTING ION CHARGES In general • metals (Mg) lose electrons ---> cations • nonmetals (F) gain electrons ---> anions