1. 10/16/2014 Take our your worksheet from yesterday! Complete your WS on determining the identity of an element before your Bell Ringer. If you get finished, copy the Bell Ringer into your journal and answer the questions. TEST tomorrow so look over your notes NOW.

2. Thursday 10/16/2014 Bell Ringer: Write and complete the statements. 1.The identity of an element is determined by _______________. 2.In a neutral atom, the # of protons equals the # of ____________. 3.The # of neutrons can change. Neutrons add ________ to the atom.

3. Thursday 10/16/2014 Bell Ringer: Write and complete the statements. 1.The identity of an element is determined by # of protons in the nucleus. A=P 2.In a neutral atom, the # of protons equals the # of electrons. A=P=E 3.The # of neutrons can change. Neutrons add mass to the atom.

4. Elements are made of only 1 kind of atom, and the atom is identified by the # of protons in the nucleus.

5. Mass Mass is the amount of matter in something. The unit of measure for atoms is amu (atomic mass unit)

6. Atomic Mass Unit 1 atomic mass unit = 1.66053886 × 10 -27 kg Kg is Kilograms

7. Relative Mass of Subatomic Particles

8. What is a Symbol?

9. Elements and Chemical Symbols Chemical Symbols / Element Names H Hydrogen O Oxygen Co Cobalt Cl Chlorine C Carbon

10. Writing Chemical Symbols 1. First letter is capitalized 2. Second letter is lower case 3. NO period at the end H Cl O Hg Fe Sn C He

11. Co or CO Does it really matter?

12. Co Cobalt-60, extensively used as a tracer and a radiotherapeutic http://members.tripod.com/duebills/27.html

13. Alloys for metals used in jet turbines Co

14. CO http://www.cpsc.gov/cpscpub/pubs/466.html Kills 200 People in United States

15. CO Produced by Incomplete Burning of Fossil Fuels

16. carbon monoxide  Colorless  Odorless  Poisonous gas carbon oxygen CO Compound

17. Think before you write a Element’s Symbol

18. Elements are substances: That cannot be broken down into other substances Made of atoms with the same number of protons in the nucleus

19. Elements are listed on the Period Table

20. Use your copy of the Periodic Table of Element Correctly write the symbol for: 1.Carbon 2.Nitrogen 3.Oxygen 4.Iron 5.Chlorine C N O Fe Cl

21. Atomic Number Number of Protons in every Atom of that Element

22. What is the name of the element with the following number of protons? A.2 B.6 C.8 D.11 E.47 Helium Carbon Oxygen Sodium Silver Use the Periodic Table

23. Protons + electrical charge Neutron No electrical charge Electrons - electrical charge + -

24. Neutral Atoms (Atoms without Electric Charge) Have equal numbers of:  Protons (+ charges)  Electrons (- charges)

25. A=P=E Atomic # = # Protons = # Electrons Because the number of positive charges equals the number of negative charges, the atom is neutral (no charge)

26. How many electrons? 1 proton 9 protons 99 protons 1 electron 9 electrons 99 electrons

27. Atomic Mass The atomic mass is listed on the individual element card on the Periodic Table.

28. Isotopes Not all atoms of the same element have the same number of neutrons. Most Carbon atoms have 6 neutrons, although some have more and some have less. Atoms of the same element with differing numbers of neutrons are called isotopes. The number of neutrons does not change the atom or the element it makes up; it just changes the mass of the atom. Most elements have isotopes.

29. Atomic Mass Number Protons + Neutrons 1. Round the Mass Number to the nearest whole number Round to 28 To calculate # of neutrons

30. Atomic Mass Number Protons + Neutrons 2. Subtract Atomic Number From Mass Number 28 (Mass #) -14 (Atomic #) 14 Neutrons Calculate # of neutrons

31. To find the AVERAGE # of Neutrons in the atom Round the atomic mass to a whole # Subtract the # of protons (also the atomic #) The difference is the average # of neutrons in the nucleus. M – A = N M is the Mass # (atomic mass) A is the atomic # (# of protons) N is the # of neutrons

32. Use the Periodic Table and Math Skills to fill in the blanks SymbolAtomic # Mass # Protons # Neutrons # Electrons He242 373 N77

33. SymbolAtomic # Mass # Protons # Neutrons # Electrons He24222 Li37343 N714777 # protons is the atomic # protons + neutrons = mass # #electrons = # protons

34. Part 2

35. Compounds 2 or More Elements Chemically Combined Oxygen Hydrogen 2-H: 1-O

36. Water H H O Ratio 2:1 Formulas use element symbols with subscript numbers H2OH2O 1 is not shown

37. Change the ratio Change the substance 2:2 H2O2H2O2 Subscript numbers http://www.wonderquest.com/images/2003-08-08-peroxide.jpg Hydrogen Peroxide

38. No subscripts?? NaCl 1Na 1Cl How many elements? Salt 2

39. Sugar C 6 H 12 O 6 How many elements?3 How many hydrogen atoms?12

40. √ Check your understanding Use your Periodic Table

41. 1. The symbol for carbon is – ACa Bc CCA DC

42. 1. The symbol for carbon is – ACa Incorrect: Symbol for calcium Bc Incorrect: 1 st letter is always a capital

43. 1. The symbol for carbon is – CCAIncorrect: C is carbon There is no element with the symbol A DC Correct: Capital C is the symbol for carbon

44. 2. How many protons are in an atom of sodium? A 11 B12 C23 D34

45. 2. How many protons are in an atom of sodium? A 11 B12 Correct: atomic # is 11 Incorrect: 12 is the number of neutrons

46. 2. How many protons are in an atom of sodium? C23 D34 Incorrect: 23 is the mass number Incorrect: No subatomic particle # is found by adding the atomic and mass numbers

47. 3.How many neutrons are there, if the mass number is 1 and the atomic number is 1? A 3 B2 C1 D0

48. 3.How many neutrons are there, if the mass number is 1 and the atomic number is 1? A 3 B2 Incorrect: There may be more or less neutrons than protons Incorrect: No subatomic particle # is found by adding the atomic and mass numbers

49. 3.How many neutrons are there, if the mass number is 1 and the atomic number is 1? C1D0C1D0 Incorrect: There is 1 proton & 1 electron Correct: 1-1 = 0

50. 4.How many electrons are in an atom of Cl? A17 B18 C35 D0

51. 4.How many electrons are in an atom of Cl? A17 B18 Correct: There are 17 + charges, so there are17 - charges Incorrect: 35-17 = number of neutrons

52. 4.How many electrons are in an atom of Cl? C35 D0 Incorrect: Mass # is the sum of protons & neutrons Incorrect: All neutral atoms have at least 1 electron

53. 5.Which of the following is a formula? A H BO CH 2 O D h2o

54. 5.Which of the following is a formula? A H BO Incorrect: Symbol for hydrogen Incorrect: Symbol for oxygen

55. 5.Which of the following is a formula? CH 2 O D h2o Correct: There are 2Elements The ratio is 2:1 Incorrect: 1 st letter is a capital 2 is not written as a subscript

56. 6.How many elements are in baking soda, NaHCO 3 ? A6B5C4D3A6B5C4D3

57. 6.How many elements are in baking soda, NaHCO 3 ? A6B5A6B5 Incorrect: There are 6 atoms Incorrect: The lower case “a” is part of the symbol for sodium

58. 6.How many elements are in baking soda, NaHCO 3 ? C4D3C4D3 Correct: 4 elements: sodium, hydrogen, carbon, oxygen Incorrect: 3 is the subscript for oxygen

59. Graphics Microsoft Clip Art Microsoft Office Online http://www.wonderquest.com/images/2003-08-08-peroxide.jpg http://www.cpsc.gov/cpscpub/pubs/466.html agenthttp://members.tripod.com/duebills/27.html http://www.wonderquest.com/images/2003-08-08-peroxide.jpg http://www.tea.state.tx.us/student.assessment/taks/booklets/science/g8e.pdf

60. Isotopes Not all atoms of the same element have the same number of neutrons. Most Carbon atoms have 6 neutrons, although some have more and some have less. Atoms of the same element with differing numbers of neutrons are called isotopes. The number of neutrons does not change the atom or the element it makes up; it just changes the mass of the atom. Most elements have isotopes.

61. Isotopes Not all atoms of the same element have the same number of neutrons. Most Carbon atoms have 6 neutrons, although some have more and some have less. Atoms of the same element with differing numbers of neutrons are called isotopes. The number of neutrons does not change the atom or the element it makes up; it just changes the mass of the atom. Most elements have isotopes.