Atomic Number

1. Atomic Number Number of Protons

2. Mass Number Number of Protons + Neutrons

3. C-12 or carbon-12 12 is the mass number.

4. 12C Left Superscript = mass number 6

5. 12C Left Subscript = atomic number 6

6. 80Br 35 35 Atomic Number = ?

7. 20Ne 10 20 Mass Number = ?

8. 238U 92 238 Mass Number = ?

9. 27Al 13 27 Mass Number = ?

10. 40Ca 20 20 Atomic Number = ?

11. 19F 9 9 Atomic Number = ?

12. U-235 Mass Number = 235 Atomic Number = 92 (Look up!) Mass Number? Atomic Number?

13. C-14 Mass Number = 14 Atomic Number = 6 (Look up!) Number of neutrons = 14 - 6 = 8 How many neutrons?

14. Isotope Atoms of the same element with a different # of neutrons

15. Isotope Atoms with the same atomic # but different mass #

16. Characteristics of Proton Charge = +1, mass = 1 amu, location = inside nucleus

17. Characteristics of Neutron Charge = 0, mass = 1 amu, location = inside nucleus

18. Characteristics of Electron Charge = -1, mass = 1/1836 amu or 0.0005 amu, location = outside nucleus

19. Ion An atom that has gained or lost electrons & so carries charge

20. Nucleons Protons & Neutrons

21. atom Smallest bit of an element that retains the properties of the element.

22. atom Electrically neutral. # of protons = # of electrons.

23. Charge # protons - # electrons

24. # of neutrons Mass number – atomic number

25. 14C 6 8 # of neutrons = ?

26. 9Be 4 5 # of neutrons = ?

27. 40Ar 18 22 # of neutrons = ?

28. 15N 7 8 # of neutrons = ?

29. 24Mg 2+ Right superscript = charge 12

30. 24Mg 2+ 10 electrons 12 # of electrons?

31. 86Rb 1+ 36 electrons 37 # of electrons?

32. 127Te 1- 53 electrons 52 # of electrons?

33. 32S 2- 18 electrons 16 # of electrons?

34. 20F - 9 protons, 11 neutrons, 10 electrons 9 # of protons, neutrons, electrons?

35. Cation Positive ion: atom lost electrons

36. Anion Negative ion: atom gained electrons

37. Avg. Atomic Mass Weighted avg. of masses of naturally occurring isotopes of an element.

38. 2 isotopes of Cl: 75% Cl-35 & 25% Cl-37.Calculate avg. atomic mass. Avg. atomic mass = .75(35) + .25(37) = 35.5 amu

39. Dalton’s Model Billiard Ball Model

40. Thomson’s Model Plum Pudding Model + - - + - + + - + -

41. Rutherford’s Model Nuclear Model - - + -

42. Rutherford’s Experiment Source: http://www.dlt.ncssm.edu/TIGER/chem1.htm#atomic

43. Most of the alpha particles went straight through.  Most of the atom is empty space. • Some of the alpha particles were deflected back.  The nucleus was tiny, but contained most of the mass of the atom. Rutherford’s Experiment: Results

44. Bohr’s Model Planetary Model

45. Schrodinger’s Model Modern or Quantum Mechanical Model Source: http://www.dlt.ncssm.edu/TIGER/chem1.htm#atomic

46. Modern Model (Schrodinger or Quantum Mechanical Model) Electron treated as a wave. Never know exactly where it is.

47. Bohr Configuration Ground state configurations found in reference tables. Cannot be predicted.

48. Bohr Configuration of Na = 2-8-1 2 electrons in energy level 1 8 electrons in energy level 2 1 electron in energy level 3

49. Bohr Diagram of Na +11

50. Valence Electron(s) Electron(s) in outermost orbit or shell