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Atomic Number

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Number of Protons Atomic Number Orbital Modern Model Region of space that holds 2 electrons. Has a specific energy. Shapes vary. E1 E2 Represents an electron dropping ... – PowerPoint PPT presentation

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Title: 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
  • 20

10
Mass Number ?
8
238U
  • 238

92
Mass Number ?
9
27Al
  • 27

13
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
  • 8

6
of neutrons ?
26
9Be
  • 5

4
of neutrons ?
27
40Ar
  • 22

18
of neutrons ?
28
15N
  • 8

7
of neutrons ?
29
24Mg
  • Right superscript charge

2
12
30
24Mg
  • 10 electrons

2
12
of electrons?
31
86Rb
  • 36 electrons

1
37
of electrons?
32
127Te
  • 53 electrons

1-
52
of electrons?
33
32S
  • 18 electrons

2-
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
Daltons Model
  • Billiard Ball Model

40
Thomsons Model
  • Plum Pudding Model


-
-
-



-
-

41
Rutherfords Model
  • Nuclear Model

-

-
-
42
Rutherfords Experiment
Source http//www.dlt.ncssm.edu/TIGER/chem1.htm
atomic
43
Rutherfords Experiment Results
  1. Most of the alpha particles went straight
    through. ? Most of the atom is empty space.
  2. Some of the alpha particles were deflected back.
    ? The nucleus was tiny, but contained most of
    the mass of the atom.

44
Bohrs Model
  • Planetary Model

45
Schrodingers 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

51
Kernel
  • Nucleus all innershell electrons Everything
    except the valence electrons

52
Bohr Model
  • Electrons are restricted to specific orbits or
    shells or principle energy levels.
  • Each shell holds a specific of electrons.
  • Each shell has a specific energy radius.
  • Energy of electron must match energy of shell.

53
Maximum Capacity of Bohr Levels
Shell Max of electrons
1
2
3
4
n
2
8
18
32
2n2
54
Ground State
  • Bohr model
  • Every electron is in the lowest available orbit.

55
2-8-7
  • Ground state configuration of Cl

56
2-6
  • Ground state configuration of O

57
Ground state configuration of Kr?
  • 2-8-18-8

58
Principle Energy Level?
  • Shell

59
Excited State
  • Bohr model
  • An electron has absorbed heat, light, or
    electrical energy and moved to a higher energy
    level.
  • Unstable. Returns to ground state quickly by
    emitting a photon.

60
2-5-1
  • An excited state of O

61
2-0-1
  • An excited state of Li

62
Continuous Spectrum
  • Spectrum produced by holding a prism in sunlight.
    Contains light at every wavelength.
  • Rainbow

63
Bright Line Spectrum
  • Visible light produced by electrons in atom
    returning to ground state light of only a few
    wavelengths is present.
  • Each element has a unique bright line spectrum.
    Used to identify elements.
  • Wavelengths of bright lines correspond to
    difference between energy levels.

Source http//www.dlt.ncssm.edu/TIGER/chem1.htm
atomic
64
Absorbtion of Energy
Excited state
E3
E2
Ground state
h?
E1
65
Emission of Energy
Excited state
h?
E3
E2
Ground state
E1
66
Orbital
  • Modern Model
  • Region of space that holds 2 electrons.
  • Has a specific energy. Shapes vary.

67
Represents an electron dropping to a lower energy
level, releasing energy in the process.
E2
E1
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