1. Number of Protons
Atomic Number

2. Number of Protons + Neutrons
Mass Number

3. Left Superscript = mass number6

4. Left Subscript = atomic number6

5. 35
80Br 35
Atomic Number = ?

6. 20
20Ne 10
Mass Number = ?

7. 27
27Al 13
Mass Number = ?

8. 20
40Ca 20
Atomic Number = ?

9. # of electrons in a neutral atom?
Neutral atoms have the same number of electrons and protons.
# of electrons in a neutral atom?

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

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

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

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

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

15. An atom that has LOST electrons
Positive Ion

16. An atom that has GAINED electrons
Negative Ion

17. # protons - # electrons
Charge

18. Protons & Neutrons
Nucleons

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

20. Mass number – atomic number
# of neutrons

21. 8 neutrons 6 protons 6 electrons
# of neutrons = ?
# of protons = ?
# of electrons = ?

22. 5 neutrons 4 protons 4 electrons
9Be 4
# of neutrons = ?
# of protons = ?
# of electrons = ?

23. 22 neutrons 18 protons 18 electrons
40Ar 18
# of neutrons = ?
# of protons = ?
# of electrons = ?

24. 8 neutrons 7 protons 7 electrons
# of neutrons = ?
# of protons = ?
# of electrons = ?

25. Right superscript = charge
24Mg 2+ 12

26. 8 neutrons 7 protons 10 electrons (gained 3)-3 7
# of neutrons = ?
# of protons = ?
# of electrons = ?

27. 10 neutrons 9 protons 10 electrons (gained 1)
19F -1 9
# of neutrons = ?
# of protons = ?
# of electrons = ?

28. 8 neutrons 8 protons 10 electrons (gained 2)-2 8
# of neutrons = ?
# of protons = ?
# of electrons = ?

29. 12 neutrons 11 protons 10 electrons (lost 1)
23Na +1 11
# of neutrons = ?
# of protons = ?
# of electrons = ?

30. 12 neutrons 12 protons 10 electrons (lost 2)
24Mg +2 12
# of neutrons = ?
# of protons = ?
# of electrons = ?

31. 14 neutrons 13 protons 10 electrons (lost 3)
27Al +3 13
# of neutrons = ?
# of protons = ?
# of electrons = ?

32. Charge on the nucleus only. Does not include the electrons.
Always positive.
Equals the number of protons.
Nuclear Charge

33. Positive ion
Cation

34. Negative ion
Anion

35. Billiard Ball Model
Dalton’s Model

36. Atoms are hard, round, indivisible. They are solid & uniform throughout.
Dalton’s model

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

38. Thomson’s model Atoms are divisible.
They are solid but NOT uniform throughout.
They contain + and - charges.
The – charges are little particles.
Thomson’s model

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

40. Atoms are divisible. Atoms are NOT solid. Atoms are NOT uniform.
They contain + and - charges.
Most of the mass and all of the + charge is concentrated in the nucleus of the atom.
Most of the volume is empty space.
Rutherford’s model

41. Rutherford’s Experiment
Shot α particles at gold foil.
Most went through, so most of the atom is empty space.
Some deflected back by small dense positive nucleus.
Rutherford’s Experiment

42. Planetary Model
Bohr’s Model

43. The mass of the entire atom: includes protons, neutrons, electrons
The mass of the entire atom: includes protons, neutrons, electrons. Expressed relative to the mass of a C-12 atom.
atomic mass

44. atomic mass unit 1 atomic mass unit  1/12 the mass of a C-12 atom. or
The C-12 atom has a mass of atomic mass units.
atomic mass unit

45. The weighted average of the masses of the naturally occurring isotopes of an element.
Average atomic mass

46. Average atomic mass Convert % abundance to decimal format.
Multiply abundance factor by appropriate mass.
Sum
Average atomic mass

47. Quick check on average atomic mass calculation.
Final answer must be between the highest & lowest masses.
Final answer will be closest to mass of most abundant isotope.
Quick check on average atomic mass calculation.

48. 75% = .75 and 25% = .25
(.75) X 35 = 26.25
(.25) X 37 = 9.25
= 35.5 = avg. atomic mass of Cl
Ans is between 35 & 37, but closer to 35.
Calculate the average atomic mass of Cl. 75% is Cl-35 and 25% is Cl-37.