Intro to Chemistry

1. Intro to Chemistry created by Mr. Nuetzel, 12/2012 sciencenuetzel@gmail.com

2. Intro to Chemistry Physical Science Core Standard Describe how atomic structures determine chemical properties and how atoms and molecules interact.

3. Periodic Table Shortcuts • The period is the horizontal row that also tells how many energy levels the atom has. • The group is the vertical column that also tells how many valence electrons there are. • The charge of an ion can be found by seeing how many columns it is from Group 8. • (Group 1 = +1, Group 5 = -3, etc.)

4. Vocabulary Terms • Element • Atom • Compound • Molecule • Nucleus • Proton • Neutron • Electron • Mass Number • Isotope • Atomic Number • Element Symbol • Subscript • Group • Valence Electrons • Reactivity or Chemical Properties • Period • Energy Levels • Charge • Positive • Loose Electrons = Positive • Negative • Gain Electrons = NEGATIVE • Ion (positive or negative) • Bond • Ionic • Covalent

5. Names for Matter • An element is a pure substance, meaning it is made up on only one type of atom. • Gold, Copper, aluminum, etc. • A compound is a mixture of multiple elements • Carbon Dioxide, Water (H2O), etc. • A molecule is a group of multiple elements and can either be pure, or made up of multiple elements. • An atomis the smallest ‘complete’ particle of one type of element

7. All matter is made up of different combinations of elements and compounds. • There are about 100 or so atoms which make up all of the natural world, but a few are much more common than others. • We could actually create a lot more elements if we wanted, but they are not normally stable (or useful).

8. Subatomic Particles • All atoms are composed of three subatomic particles: • Protons • Positive charge, found in the nucleus • Neutrons • Neutral charge, found in the nucleus • Electrons • Negative charge, found in electron cloud

9. Atomic Pictures

10. Atomic Pictures

11. Scale and Structure Location • Protons and neutrons are located in the center, densely packed together. • Penny on second base of Baseball diamond • Electrons orbit the nucleus in different energy levels in the electron cloud. • Flying around the outside of the stadium

12. Scale and Structure Mass • Protons and neutrons are very similar and size • Electrons are much, much smaller than the others particles • Fly vs. Garbage Truck

13. Writing Elements R = Chemical Symbol M = Mass Number A = Atomic Number C = Charge C R M A

14. Isotopes • NOT all atoms in an element are EXACTLY the same. GENERAL RULES • Protons determine the IDENTITY of an atom • Neutrons determine the ISOTOPE. • Electrons determine the CHARGE

15. Elements and Numbers • Atomic Number • This tells the number of Protons in an atom • This is also the basic number of Electrons in an atom • Atoms do not gain or lose protons, but ONLY electrons. When this happens the charge on the atom will change. If an atom were to lose a proton it would become a different type of atom • Mass Number • This tells the number of Neutrons + Protons in an isotope

16. Isotopes C C C 12 13 14 6 6 6

17. Charges • a Proton = +1 charge • a Neutron = 0 charge • an Electron = -1 charge

18. When an atom gains electrons • It becomes MORE negatively charged • When an atom loses electrons • It becomes MORE positively charged • When an atom is a different Isotope • It doesn’t affect the charge

19. The Periodic Table of Elements

21. Periodic – appearing or occurring at intervals • The number of outer electrons equals the group. • The number of energy levels equals the period. • Group = Vertical Column • Period = Horizontal Row

22. Periodic Table Shortcuts • The period is the horizontal row that also tells how many energy levels the atom has. • The group is the vertical column that also tells how many valence electrons there are. • The charge of an ion can be found by seeing how many columns it is from Group 8. • (Group 1 = +1, Group 5 = -3, etc.)

24. Group 5, Period 3

25. Group 5, Period 3

26. Group 5, Period 3

27. Group 5, Period 3

28. Group 5, Period 3

29. Period 5, Group 8

30. Period 5, Group 8

31. Period 5, Group 8

32. Period 5, Group 8

33. Period 5, Group 8

34. Periodic Table Shortcuts • The period is the horizontal row that also tells how many energy levels the atom has. • The group is the vertical column that also tells how many valence electrons there are. • The charge of an ion can be found by seeing how many columns it is from Group 8. • (Group 1 = +1, Group 5 = -3, etc.)

35. Essential Questionsfrom Atomic Structure Notes • #1 - What is the relationship between an atom and an element? • #2 - How are protons and neutrons different from and similar to each other? • #3 - How do electrons differ from both protons and neutrons? • #4 - How are protons, neutrons, and electrons arranged to form an atom?

36. EQ#1 - What is the relationship between an atom and an element? • An element is a pure substance made up of one type of matter or one kind of atom. The atom is the smallest possible complete or ‘unique’ piece of matter. When you completely break that pure compound element into smaller pieces they are not specific to one type of substance. For example, 2 protons, 2 neutrons, and 2 electrons is helium, but if you break that in half you get a different atom, hydrogen (with an extra neutron) which isn’t easily broken apart without large sums of energy.

37. EQ#2 - How are protons and neutrons different from and similar to each other? • Protons and neutrons are both located inside of the nucleus and they both have equal one atomic mass unit. They are different because they have different charges, the proton being positively charged, and the neutron being negatively charged. The number of protons determines the identity of the atom, but the number of neutrons determines which isotope of a certain element it is.

38. EQ#3 - How do electrons differ from both protons and neutrons? • The electron is much smaller in mass than either a proton or neutron. It is located in a different place within the atom, and it has a negative charge, unlike the other sub-atomic particles. The electrons do not determine the type of atom, but they do have an effect on the properties of an element. Elements with the same number of valance electrons generally bond like each other.

39. EQ#4 - How are protons, neutrons, and electrons arranged to form an atom? • The protons and neutrons are located in the nucleus, the very dense center of the atom. Almost all of the mass of the atom is located in this small center. On the outside, in different energy levels electrons speed around the atom, pulled near by the electro-static force between positive and negative charges. The electrons orbit at a relatively far distance within the atom. Most of the atom is empty space.

40. Element Families • Noble Gases • Do Not React With Others • Happy / Stable = Full Outer Energy Level! • Alkali Metals • Hoping to lose 1 electron • Halogens • Greedy for electrons

41. Glencoe Ch. 6 Vocab and Terms Section 1 • Neutral • Electron Cloud • Energy Levels • 2, 8, 8… • Groups • Electron Dot Diagram • Valence Electrons (8*) • Chemical Bond Section 2 • Ions • Ionic Bonds • Compound • Covalent Bond • Molecule • Polar Bond • Uneven Sharing • Chemical Formulas

42. Glencoe Science Ch. 6 Summary The protons determines the type of element, while the electrons determine the reactivity of the element. If the protons and electrons are the same, it is neutral. All atoms would rather be stable, with 8* valence electrons as shown in Electron Dot Diagrams. Elements with the same number of valence electrons form the families on the periodic table. Ionicbonding involves gaining/ losingelectrons forming compounds between metals and nonmetals. Covalentbondinginvolves sharingelectrons between nonmetals forming molecules, which are either polarornon-polar. In a polar bond, one atom pulls more on the electron, giving it have positive and negative “pole”. Non-polar bonds equally shared electrons and are symmetrical.

44. Counting Atoms in Formulas • Subscript= this tells the number of each atom in a compound. If there is no subscript we know that it is one atom. H2O • Parenthesis + Subscripts= sometimes there will be a parenthesis with a subscript after it. This means that you need to multiply all of the atoms in the parenthesis by the subscript outside of the parenthsis. Fe3(PO4)2 * Superscript– shows the charge on an ion

45. ChemicalFormulas Symbols = the type of atom Subscripts = the number of each atom Sodium Chloride - NaCl Methane - CH4 Ibuprofen – C3H8O2C10H10

46. ChemicalFormulas Symbols = the type of atom Subscripts = the number of each atom Plavix (heart medication) – C4H12ClC4NC4O2SC4H4 Thymaine- C5H4N2(OH)2

47. Ionic Bonding We know that opposites attract, so oppositely charged ions will join together to form compounds. Ionic Bonding occurs between Metals and Non-metals

48. Ions • Electrons have negative charges. Protons have positive charges. An atom has no netcharge while the protons and electrons are equal. • To form an ion, an element will gain or lose electrons until it has a complete outer energy level (HAPPY) • An element would rather be happy than neutral. • Gain electrons = net negative charge. • Lose electrons = netpositive charge.

49. Compounds – opposites attract! • Positive Ions will attract Negative Ions. • A +1 ion will equally bond with a -1 ion. • A +2 ion will equally bond with a -2 ion. • What about when a +2 ion encounters a -1 ion?

50. Making Compounds = Making Elements Happy Compound E-Harmony • Draw EDD’s • Figure out the Charge that the 2 Ions will make. • Multiply the + ions and – ions until they cancel. • Write the formula with the correct subscripts. Na + Cl