Ch 4 Section 2 Flashcards Preview

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Flashcards in Ch 4 Section 2 Deck (70):
1

Investigations into the photoelectric reflect and hydrogen a emission line spectrum revealed that

Light could behave as both a wave and a particle

2

French scientist Louis de broglie suggested that electrons be considered

Waves confined to the space around an atomic nucleus

3

It followed that the electron waves could only exist at

Specific frequencies

4

According to the relationship E= hv these frequencies corresponded to

Specific energies, the quantized energies of Bohr's orbits

5

Electrons like light waves can be

Bent (diffracted)

6

Diffraction reefers to the

Bending of a wave as it passes by the edge of an object or through a small opening

7

Electron beams like waves can

Interfere with each other

8

Interference occurs when

Waves overlap

9

Overlapping results in a

Reduction of energy in some areas and an increase of energy in others

10

Heisenbergs proposal answers question of

Where electrons are located if they are both particles and waves

11

Heisenbergs idea involved the

Detection of electrons

12

Electrons are detected by their

Interaction with photons

13

Because photons have about the same energy as electrons any attempt to locate a specific electron with a photon

Knocks the electron off its course

14

The Heisenberg uncertainty principle stated that it is impossible to

Determine simultaneously both the position and velocity of an electron or any other particle

15

Heisenberg uncertainty principle is One of the fundamental principles of our

Present understanding of light and matter

16

In 1926 Austrian physicist Erwin schrodinger used the hypothesis that electrons have a dual wave particle nature and

Developed an equation that treated electrons in atoms as waves

17

To explain why atomic energy states are quantized scientists had to change

The way they viewed the nature of the electron

18

Quantization I'd electron energies was a natural outcome of

Schrodingers equation

19

Only waves of specific energies and therefore frequencies

Provided solutions to the equation

20

Together with the Heisenberg uncertainty principle the schrodinger wave equation laid the

Foundation for modern quantum theory

21

Quantum theory describes mathematically the

Wave properties of electrons and other very small particles

22

Solutions to the schrodinger wave equation are known as

Wave functions

23

Based on the Heisenberg uncertainty principle the early developers of quantum theory determined that wave functions give only the

Probability of finding an electron at a given place around the nucleus

24

Electrons do not travel around the nucleus in

Neat orbits as Bohr had postulated

25

Instead electrons. Exist in certain regions called

Orbitals

26

Am ornital is a

3d region around the nucleus that indicates the probably location of an electron

27

According to the schrodinger equation electrons in atomic orbitals also have

Quantized energies

28

An electrons energy level is not the only characteristic of an orbital that is indicated by

Solving the schrodinger equation

29

Quantum numbers specify the properties of

Atomic orbitals and the properties of electrons in orbitals

30

The first 3 quantum numbers result from

Solutions to the schrodinger equation. They indicate the main energy level shape and orientation of an orbital

31

The fourth, spin quantum number, describes a

Fundamental state of the electron that occupied the orbital

32

The principal quantum number symbolized by n indicated the

Main energy level occupied by the electron

33

Values of n are

Positive integers only

34

As n increases the electrons energy and its average distance from the nucleus

Increase

35

An electron for which n = 1 occupied the

First (lowest) main energy level and is located closest to the nucleus

36

More than one electron can have the same

N value. These electrons are sometimes said to be in the same electron shell

37

Total number of orbitals that exist in a given she'll is

N^2

38

Except at the first main energy level orbitals of different

Shapes--known as sublevels-- exist for a given value of n

39

The angular momentum quantum number symbolized by l indicates the

Shape of the orbital

40

For a specific main energy level the number of orbital shapes possible is

Equal to n

41

The values of l allowed are

zero and all positive integers less than or equal to n-1

42

Depending on its value of l an orbital is

Assigned a letter

43

S orbitals are

Spherical

44

p orbitals have

Dumb bell shapes

45

D orbitals are more

Complex

46

In the first energy level n=1

There is only one sublevels possible an s orbital

47

second energy level n=2 has

2 sublevels the s and p orbitals

48

In the nth main energy level there are

N sublevels

49

Each atomic orbital is designated by the

Principal quantum number followed by the letter of the sublevels

50

Atomic orbitals can have the same

Shape but different orientations around the nucleus

51

The magnetic quantum number symbolized by m indicated the

Orientation of an orbital around the nucleus

52

Values of m are whole numbers including

Zero from -l to +l

53

Because an s orbital is spherical and is centered around the nucleus it has

Only one possible orientation

54

S Orientation corresponds to a magnetic quantum number of

M = 0

55

Only one s orbital in each

Sublevels

56

The loves of a p orbital extend along the

X y or z axis of s 3 dimensional coordinate system

57

There are 3 p orbitals in each

P sublevel which are designation as px py pz

58

The 3 p orbitals occupy different regions of space and those regions are related to values of

M = 0 m = -1 m =+ 1

59

There are 5 different d orbitals in each

D sublevel

60

Five different orientations of d correspond to values of

M = -2. M = -1 m = 0 m= 2 m= 1

61

There are 7 different f orbitals in each

F sublevel

62

The total number of orbitals in a main energy level increases with

The value of n

63

Number of orbitals at each main energy level equals the

Square of the principal quantum number n^2

64

The electron exists in one of two possible

Spin states which creates a magnetic field

65

To account for the magnetic properties of the electron theoreticians created the

Spin quantum number

66

The spin quantum number has only two values (+1/2, -1/2) which indicate

The two fundamental spin states of an electron in an orbital

67

A single orbital can hold a maximum of

Two electrons but the two electrons must have opposite spin states

68

Number of orbitals in sublevel

2l + 1

69

Number of electrons possible in sublevel

[2(2l + 1)]

70

Total electrons possible for energy level

2n^2