Ch 4 Section 1 Flashcards Preview

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Flashcards in Ch 4 Section 1 Deck (63):
1

Visible light is a kind of

Electromagnetic radiation

2

Together all the forms of electromagnetic radiation form the

Electromagnetic spectrum

3

Wavelength is the distance between

Corresponding points on adjacent waves

4

Significant feature of wave motion is its

Rewriting nature which can be characterized by wavelength and frequency

5

Unit for wavelength

Distance unit (m, cm, nanometer)

6

Frequency (v) is defined as the number of

Waves that pass a given point in a specific time usually one second

7

Frequency unit

Waves per second (hertz)

8

Frequency and wavelength are

Mathematically related to each other
C = wavelength times frequency

9

In wavelength frequency equation c is the

Speed of light

10

In wavelength frequency equation wavelength symbol is the

Wavelength of the electromagnetic wave in m

11

In wavelength frequency equation v is the

Frequency of the electromagnetic wave in s^-1

12

In wavelength frequency equation the product is a

Constant

13

Wavelength is

Inversely proportional to v

14

As wavelength decreases

Frequency increases

15

The photoelectric effect refers to the

Emission of electrons from a metal when light shines on the metal

16

Wave theory of light predicted that light of any frequency could supply enough

Energy to eject an electron

17

A quantum of energy is the minimum quantity of

Energy that can be lost or gained by an atom

18

Max Planck proposed the following relationship between a quantum of energy and frequency of radiation:

E = hv

19

In equation E = hv, e is the

Energy in joules of a quantum of radiation

20

In equation E = hv, v is the

Frequency in s^-1 of the radiation emitted

21

In equation E = hv, and h is a fundamental

Physical constant known as plancks constant

22

Plancks constant

6.626 x 10^-34 J • s

23

Einstein introduced idea that electromagnetic radiation has a

Dual wave particle nature

24

Electromagnetic radiation is a form of energy that exhibits

Wavelike behavior as it travels through space

25

A photon is a particle of electromagnetic radiation having

Zero mass and carrying a quantum of energy

26

The energy of a particular photon spends on the

Frequency of the radiation

27

Ephoton =

Hv

28

Electromagnetic radiation is absorbed by matter only in

While numbers of photons

29

Different metals require different

Minimum frequencies to exhibit the photoelectric effect

30

When current is passed through gas at low pressure the

Potential energy of the gas atoms increases

31

Ground state of an atom

Lowest energy state of an atom

32

Excited state of an atom is a state in which an atom has a

Higher potential energy than it has in its ground state

33

When an excited atom returns to its ground state or lower energy excited state it gives off

Energy it gained in form of electromagnetic radiation

34

When investigators passed electric current through a vacuum tube containing hydrogen gas at low pressure the observed

The emission of a characteristic pinkish glow

35

When a narrow beam of the emitted light was shined through a prism it was

Separated into four specific colors of the visible spectrum

36

The four bands of emitted light were part of what is known as

Hydrogens line emission spectrum

37

Scientists had expected to observe the emission of a

Continuous range of frequencies of electromagnetic radiation: continuous spectrum

38

New atomic theory called the

Quantum theory

39

Whenever an excited hydrogen atom falls to its ground state or to lower energy excited state it emits a

Photon of radiation

40

The fact that hydrogen atoms emit only specific frequencies of light indicated that

Energy differences between atoms' energy stars were fixed

41

Niels Bohr proposed a hydrogen atom model that linked the atoms

Electron to photon emission

42

According to the model the electron can

Circle the nucleus only in allowed paths (orbits)

43

When the electron is in one of these orbits atom has a

Definite fixed energy

44

The electron is in its lowest energy state when it is in the

Orbit closest to the nucleus

45

This orbit is separated from the nucleus by a

Large empty space where the electron cannot exists

46

The energy of the electron is higher when the electron is in orbits that are

Successively farther from the nucleus

47

An electron can be in one orbit or another but not

In between

48

While in a given orbit the electron is neither

Gaining nor losing energy

49

When an electron falls to a lower energy s photon is emitted and the process is called

Emission

50

Energy must be added to an atom in order to

Move an electron from a lower energy level to a higher energy level (absorption)

51

Energy of each absorbed or emitted photon corresponds to a

Particular frequency of emitted radiation
Ephoton= hv

52

Bohr's approach did not explain the spectra of atoms with

More than one electron

53

Other kinds of electromagnetic radiation

X Rays
Ultraviolet and infrared light
Microwaves
Radio waves

54

All forms of electromagnetic radiation move at a constant speed though a vacuum of

3.00 x 10^8 meters per second

55

3,00 x 10^8 m/s is also lights

Approximate speed through air
C

56

The mystery of the photoelectric effect invoked the

Frequency of the light striking the metal

57

Max Planck studied the emission of light by

Hot objects

58

Planck proposed that a hot object does not emit

Electromagnetic energy continuously

59

Planck suggested that the object emits energy in

Small specific packets called quanta

60

The energy of this photon is equal to the difference in

Energy between the atoms Initial state and its final state

61

Bohr calculated the allowed

Energy levels for the hydrogen atom

62

Bohr related the possible energy level changes to the

Lines in the hydrogen emission line spectrum

63

Bohr's theory didn't explain the chemical

Behavior of atoms