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