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Chapter 1 L.1,2 Atomic theories

Total questions: 119

Worksheet time: 2hrs 40mins

Name
Class
Date
1.

Rutherford made important contributions to atomic theory. What did his model fail to explain?

a)

location of protons

b)

why the negatively charged electrons were not pulled into the positively charged nucleus

c)

location of neutrons

d)

none of the above

2.

Which statement describes how electrons fall from the excited state of energy back to the ground state?

a)

Energy is absorbed

b)

Energy is released and a photon of light is emitted

c)

the electron seeks energy

d)

none of the above

3.

What was Rutherford’s major contribution to atomic theory?

a)

the arrangement of electrons

b)

the existence of a small, dense, positively charged nucleus

c)

The existence of radioactivity in the nucleus

d)

The discovery of the neutron

4.

__________ conducted the cathode ray tube experiment and discovered the electron.

a)

JJ Thomson

b)

Ernest Rutherford

c)

Niels Bohr

d)

Democritus

5.

______ discovered the neutron in 1932 and won the Nobel Prize for Physics in 1935.

a)

Ernest Rutherford

b)

Niels Bohr

c)

James Chadwick

d)

JJ Thomson

6.

In the _________ of the atom, electrons are in the electron cloud and have a probability of being located inside three-dimensional regions around the nucleus referred to as atomic orbitals.

a)

Rutherford Model

b)

Quantum Mechanical Model

c)

Bohr Model

d)

Plum Pudding Model

7.

Developed by JJ Thomson and later discredited by Ernest Rutherford, this model of the atom is described by the existence of a positively charged sphere with electrons embedded within it.

a)

Bohr Model

b)

Rutherford Model

c)

Schrodinger's model

d)

Plum Pudding Model

8.

____________ suggested that the electron in a hydrogen atom moves around the nucleus in certain allowable circular orbits.

a)

Ernest Rutherford

b)

Erwin Schrodinger

c)

Niels Bohr

d)

James Chadwick

9.

John Dalton, JJ Thomson, Niels Bohr, Ernest Rutherford, James Chadwick, Erwin Schrodinger, and Louis de Broglie, and several other scientists contributed to the body of knowledge known as atomic theory. What do the changes made to atomic theory and the evolution of this body of knowledge demonstrate about the scientific process?

a)

Experimentation is key to yielding valid results

b)

Scientists need to replicate prior experiments to validate their findings.

c)

Theories change as new information becomes available

d)

Competition and financial gain drive scientific inquiry

10.

___________ proposed a model of the hydrogen atom that sought to explain the relationship between atomic emissions spectra and the energy states of atoms.

a)

JJ Thomson

b)

Ernest Rutherford

c)

Niels Bohr

d)

John Dalton

11.

Rutherford conducted the ____________ and published his work in 1911.

a)

Cathode Ray Tube Experiment

b)

Plum Pudding Experiment

c)

Gold Foil Experiment

d)

None of these

12.

An electron is said to be in its _____ state when it occupies the lowest possible energy level of an atom.

a)

ground

b)

excited

c)

emissions

d)

none of the above

13.

Which of the following was a limitation of the Bohr Model?

a)

He only theorized that atoms are the building block of matter.

b)

Failed to understand the charges of protons and electrons

c)

Did not explain the movement of electrons or the interaction between the subatomic particles.

d)

Did not know the existence of subatomic particles.

14.

The atom was first conceptualized by ______ in _____ who observed that rocks broken into several pieces retained their properties.

a)

John Dalton; 1803

b)

Democritus; 400 BC

c)

Ernest Rutherford; 1911

d)

James Chadwick; 1932

15.

Which of the flowing statements is true regarding subatomic particles?

a)

protons and electrons are located inside the nucleus

b)

protons and neutrons are located inside the nucleus

c)

protons and electrons are located outside of the nucleus

d)

neutrons are located outside of the nucleus

16.

Which of the following was NOT a conclusion described by John Dalton’s work?

a)

All matter is made up of tiny particles called atoms.

b)

Electrons are in the electron cloud

c)

Atoms are indivisible and indestructible

d)

Atoms rearrange in simple, whole-number ratios during chemical reactions because mass is conserved.

17.

JJ Thomson was credited for the discovery of the:

a)

Center of the universe

b)

Proton

c)

Electron

d)

Neutron

18.

The first universally accepted theory on atoms was proposed in 1803 by:

a)

Winston Churchill

b)

John Dalton

c)

James Bond

d)

J J Thomson

19.
What scientist is best known for his "Plum Pudding" model of the atom?
a)
J.J. Tomson
b)
Ernest Rutherford
c)
John Dalton
d)
Democritus
20.
What contribution did John Dalton make to atomic theory? 
a)

He discovered that every atom was positively charged.

b)

He discovered that every element consisted of one type of atom 

c)

He discovered that atoms had nuclei 

d)

He discovered that atoms could be divided into smaller parts

21.

Niels Bohr suggested that electrons:

a)

Are found in specific orbits

b)

Are scattered throughout the atom

c)

Move according to their energy level

d)

Are positive

22.

Rutherford discovered this part of the atom:

a)

Nucleus

b)

Neutron

c)

Proton

d)

Electron

23.

Which conclusion could be made from Ernest Rutherford’s gold foil experiment?

a)

Atoms are made up of mostly empty space.

b)

Atoms are mainly solid and block alpha particles.

c)

The volume of the nucleus is large compared to the rest of the atom.

d)

The mass of the nucleus is small compared to the rest of the atom.

24.

What did Ernest Rutherford’s gold foil experiment demonstrate about atoms?

a)

Their positive charge is located in a small region that is called the nucleus.

b)

Their negative charge is located in small particles that are called electrons.

c)

Their nucleus makes up the majority of the volume of the atom.

d)

Their electrons are floating in a sea of positive charges.

25.

What is the correct order of scientists in order of their work related to the atomic theory from earliest to most recent?

a)

Ernest Rutherford, JJ Thomson, John Dalton, & Democritus

b)

JJ Thomson, John Dalton, Ernest Rutherford, & Democritus

c)

Democritus, John Dalton, JJ Thomson, Ernest Rutherford.

d)

John Dalton, JJ Thomson, Democritus, & Ernest Rutherford

26.

Which one of these is Dalton's Model?

a)
b)
c)
d)
27.

Why did Ernest Rutherford and his colleagues perform the Gold-Foil Experiment?

a)

They wanted to test and confirm the Plum-Pudding model

b)

They wanted to test John Dalton's Model

c)

They were looking for electrons

d)

They wanted to come up with their own Atomic Model

28.

Which of the following was an observation made by Rutherford to support that atoms have a dense positive nucleus?

a)

He observed that all alpha particles did go through a gold-foil in straight lines

b)

He observed that most alpha particles did not go through a gold-foil and stopped on one side of the gold foil.

c)

He observed that a small number of alpha particles bounced off the gold-foil at very large angles

d)

He observed that all alpha particles slightly deflected from the straight line when going through a gold-foil

29.
Line emission spectrum shown below happens when
a)
Electron transition from lower to higher energy level.
b)
Electron transition from higher to lower energy level.
c)
Electron exist in fixed energy states
d)
Electron transition between different energy levels.
30.
For an electron to change from ground state to an excited stated it must...
a)
Absorb energy
b)
Release energy
31.

If an electron moves from n=4 to n=2 it ____

a)

absorbs energy

b)

releases energy

32.
Which elements are in the unknown sample?
a)
A and B
b)
B and C
c)
A and D
d)
B and D
33.

This is the distance between two peaks. What is this called?

a)

amplitude

b)

wavelength

c)

longitude

d)

trough

34.

The lower the frequency the ______ the energy.

a)

higher

b)

lower

c)

neither, stays the same

35.
High frequency waves have _________ wavelengths.
a)
varying
b)
long
c)
the same
d)
short
36.
Which wave has a greater frequency?
a)
A
b)
B
37.

JJ Thomson used a cathode ray tube to discover what about the atom.

a)

The atom is mostly empty space

b)

The atom has a positive, solid core called a nucleus

c)

Atoms have electrons that have a negative charge

d)

Atoms have electrons that have a positive charge.

38.

Rutherford discover what about the atom when most of the alpha particles went straight through the gold foil.

a)

The atom is mostly empty space

b)

The atom has a positive, solid core called a nucleus

c)

Atoms have electrons that have a negative charge

d)

Atoms have electrons that have a positive charge.

39.

Rutherford discover what about the atom when a tiny percent of alpha particles either deflected or bounced off of the gold foil?

a)

The atom is mostly empty space

b)

The atom has a positive, solid core called a nucleus

c)

Atoms have electrons that have a negative charge

d)

Atoms have electrons that have a positive charge.

40.

JJThomson proved what wrong about Democritis theory when he discovered a negative particle within the atom?

a)

He proved that the atom can be divided (not indivisible)

b)

He proved tha the atom should not be called the atomos

c)

He proved that democritis has no evidence to back up his findings.

d)

He proved that Rutherford would agree with him about the atom being neutral.

41.

The only part of Democritis theory we kept until today is which of the following.

a)

The atom is indivisible

b)

The atom' s name comes from "atomos"

c)

All atoms are made up of the same material.

d)

All atoms are made up of different material.

42.

JJ Thompson's model was called the _______________ model.

a)

Nuclear model because it had a nucleus

b)

The solid sphere model becuase all atoms where not divisible.

c)

The planetary model because Electron orbit around a nucleus.

d)

The plum pudding model because there were a lot of electron in a positive cloud.

43.

Which scientist had no scientific data to back up his atomic theory- he did not experiments.

a)

JJ Thomson

b)

Rutherford

c)

Dalton

d)

Democritis

44.

Dalton discover what about the atom after doing many chemical reactions and weighing the masses before and after his experiments.

a)

The atom is mostly empty space

b)

The atom has a positive, solid core called a nucleus

c)

Conservation of mass- The mass in the beginning of a reaction will be the same at the end of a reaction.

d)

Atoms have electrons that have a positive charge.

45.

Dalton also discover what about the atom after doing many chemical reactions.

a)

The atom is mostly empty space

b)

The atom has a positive, solid core called a nucleus

c)

Atoms always react in whole number ratios.

d)

Atoms have electrons that have a positive charge.

46.

Rutherfords gold foil experiment used the which concept of charges?

a)

“Like” charges repel each other, and “unlike” charges repel each other.

b)

“Like” charges attract each other and “unlike” charges attract each other

c)

“Unlike” charges repel each other and “like” charges attract each other.

d)

“Unlike” charges attract each other and “like” charges repel each other.

47.

What is the final Quantum mechanical model based on from all the atomic theories.

a)

Only based on Rutherford and Thomson's theories.

b)

It is a combination of all the scientist's atomic theories over the past 1000 years, but mostly based on Rutherford's positive nucleus and Schrodinger's and Heisenberg's electron cloud.

c)

Only basedon Heisenberg/Schrodinerg electron cloud and Thomson's theories.

d)

It is a combination of Democritis, Dalton and Rutherford only.

48.

How did Dalton prove Democritis wrong?

a)

He discovered the electron proving that the atom could be divided

b)

He discovered that atoms are made up of different material not the same material through chemical reactions.

c)

He discovered that the atomos was not a good name and changed it to the atom.

d)

He only agreed with Democritis on his theories about the atom.

49.

(From the video we watched) Who discovered that electrons have to be in quantized energy levels or they will crash into the nucleus.

a)

JJ Thomson

b)

Rutherford

c)

Dalton

d)

Bohr

50.

Used the word "atomos" to decsribe the uncuttable (indivisible) atom.

a)

Democritus

b)

Thomson

c)

Bohr

d)

Dalton

51.

Proposed that electrons move around the nucleus in specific layers, or shells.

a)

Bohr

b)

Rutherford

c)

Chadwick

d)

Thomson

52.

This picture best represents ___________________ atomic model.

a)

Thomson's

b)

Dalton's

c)

Bohr's

d)

Chadwick's

53.

Which one of these is Dalton's Model?

a)
b)
c)
d)
54.

Which model was created after the discovery of the nucleus?

a)

Dalton's

b)

Rutherford's

c)

Quantum Mechanical

d)

Plum Pudding

55.

Which model was created after the discovery of the electron cloud?

a)

Dalton's

b)

Rutherford's

c)

Quantum Mechanical

d)

Plum Pudding

56.

Who discovered electrons?

a)

Rutherford

b)

Bohr

c)

J.J. Thompson

d)

Democritus

57.
Ernest Rutherford discovered that the atom was mostly _________________ and has a _______________ charged nucleus.
a)
empty space, positively
b)
empty space, negatively
c)
full of protons, positively
d)
full of neutrons, negatively
58.

Within Dalton's Atomic Theory, he had proposed...

a)

Atoms were the smallest particles that existed and could be divisible

b)

Atoms were the smallest particles that existed and were round

c)

Atoms were the smallest particles that existed and could not be divisible

59.
Which scientist proposed that all matter is composed of atoms, which he assumed were indivisible and indestructible building blocks of nature.
a)
J. J. Thompson
b)
John Dalton
c)
Neils Bohr
d)
Ernest Rutherford
60.

Which experiment was performed by J. J. Thomson in 1897?

a)
Oil Drop Experiment
b)
Gold Foil Experiment
c)
Wave  Experiment
d)
Cathode Ray Experiment
61.
Which subatomic particle was discovered as a result of the cathode ray experiment?
a)
proton
b)
neutron
c)
electron
d)
nucleus
62.
Who performed the Gold Foil Experiment?
a)
J. J. Thomson
b)
Ernest Rutherford
c)
Neils Bohr
d)
John Dalton
63.
Which model was proposed by Neils Bohr?
a)
Planetary Model
b)
Plum Pudding Model
c)
Quantum Mechanical Model
d)
Solid Ball Model
64.
Which of the following were outcomes of the Gold Foil Experiment?  
a)
Electrons occupy different energy levels orbiting the nucleus.
b)
Electrons are negatively charged subatomic particles.
c)
Electrons orbit the empty space around the dense positive nucleus.
d)
Electrons move in wave patterns around the nucleus
65.
Which subatomic particle was discovered by James Chadwick?
a)
proton
b)
neutron
c)
electron
d)
quark
66.
All of the following of Dalton's theories were correct EXCEPT - 
a)
All atoms are identical.
b)
All matter is made of atoms.
c)
Chemical reactions rearrange atoms.
d)
Compounds contain different atoms.
67.

The first scientist who defined the atom is.............

a)

Dalton

b)

Aristotle

c)

Democritus

d)

Thomson

68.

Matter is composed of four components (water, air, dust and fire) with different proportions. That idea belongs to........

a)

Bohr

b)

Rutherford

c)

Dalton

d)

Aristotle

69.

..........hypothesized that the compounds are composed of certain elements combined in a simple numerical ratio.

a)

Dalton

b)

Schrodinger

c)

Thomson

d)

Bohr

70.

The cathode rays consist of very fine particles called.............

a)

α-particles.

b)

electrons

c)

protons

d)

photons

71.

Electric discharge experiment of Thomson proved that the atom..................

a)

is solid

b)

contains a vast space.

c)

contains a positively charged nucleus

d)

contains negatively charged electrons.

72.

The .................rays are deflected towards the positive pole when they are affected by the electric field.

a)

alpha

b)

cathode

c)

gamma

d)

X

73.

The metal sheet used in Rutherford's experiment is lined with a layer of ...............

a)

ZnS2

b)

ZnSO3

c)

Zn2S

d)

ZnS

74.

The scientist who discovered that the electrons have a negligible mass if it is compared to that of the nucleus is.............

a)

Thomson

b)

Bohr

c)

Rutherford

d)

Dalton

75.

When alpha rays fall on the gold foil, ............of them penetrate it.

a)

most

b)

all

c)

a small fraction

d)

the average

76.

The scientist who designed the first model of the atomic structure on an experimental basis is .....................

a)

Rutherford

b)

Bohr

c)

Berzelius

d)

Schrodinger

77.

Matter is composed of four components (water, air, dust and fire) with different proportions. That idea belongs to........

a)

Bohr

b)

Rutherford

c)

Dalton

d)

Aristotle

78.

The first scientist who defined the atom is.............

a)

Dalton

b)

Aristotle

c)

Democritus

d)

Thomson

79.

..........hypothesized that the compounds are composed of certain elements combined in a simple numerical ratio.

a)

Dalton

b)

Schrodinger

c)

Thomson

d)

Bohr

80.

Electric discharge experiment of Thomson proved that the atom..................

a)

is solid

b)

contains a vast space.

c)

contains a positively charged nucleus

d)

contains negatively charged electrons.

81.

The cathode rays consist of very fine particles called.............

a)

α-particles.

b)

electrons

c)

protons

d)

photons

82.

The .................rays are deflected towards the positive pole when they are affected by the electric field.

a)

alpha

b)

cathode

c)

gamma

d)

X

83.

The metal sheet used in Rutherford's experiment is lined with a layer of ...............

a)

ZnS2

b)

ZnSO3

c)

Zn2S

d)

ZnS

84.

The scientist who discovered that the electrons have a negligible mass if it is compared to that of the nucleus is.............

a)

Thomson

b)

Bohr

c)

Rutherford

d)

Dalton

85.

When alpha rays fall on the gold foil, ............of them penetrate it.

a)

most

b)

all

c)

a small fraction

d)

the average

86.

The scientist who designed the first model of the atomic structure on an experimental basis is .....................

a)

Rutherford

b)

Bohr

c)

Berzelius

d)

Schrodinger

87.

if the ethylene is C2H4 , then the atomic ratio of the Hydrogen to the carbon respectively is ------------

a)

2:4

b)

4:2

c)

1:2

d)

2:1

88.

Cathode rays ------

a)

has mass only

b)

has charged only

c)

has both mass and charge

d)

do not have either mass or charge

89.

if you know that the aromatic benzene formula is C6H6 . then the elements ratio is -------- [C=12; H=1]

a)

6:6

b)

1:6

c)

1:1

d)

3:3

90.

What is the mass ratio of the carbon to the hydrogen in the Methane CH4 [if C=12; H=1]

a)

1:4

b)

3:2

c)

3:1

d)

4:1

91.

Which model was created after the discovery of the electron cloud?

a)

Dalton's

b)

Rutherford's

c)

Quantum Mechanical

d)

Plum Pudding

92.

Determined that electron paths cannot be predicted and exist inside the Electron Cloud.

a)

Ernest Schrodinger

b)

Ernest Rutherford

c)

John Dalton

d)

Democritus

93.
Which is the correct sequence of the scientists who made major changes in the model of the atom?
1-JJ Thomson
2-Erwin Schrodinger
3-John Dalton
4-Niels Bohr
5-Ernest Rutherford
a)
2, 1, 4, 3, 5
b)
3, 1, 5, 4, 2
c)
5, 3, 2, 1, 4
d)
4, 3, 2, 1, 5
94.

Who proposed the theory that atoms orbit the nucleus in specific orbits.

a)

Bohr

b)

Democritus

c)

Rutherford

d)

Chadwick

95.
Define "quantized"
a)
The electron's mass is very small. 
b)
The electron is actually a wave.
c)
The position & momentum of the electron cannot be known at the same time. 
d)
The electron is limited to certain positions in the atom.
96.
What is the Pauli Exclusion Principle?
a)
An atomic orbital can only hold a maximum of 2 electrons, each with opposite spins
b)
An atomic orbital can hold a minimum of 6 electrons, each with opposite spins
c)
An atomic orbital can hold a maximum of 6 electrons, each with the same spin
d)
An atomic orbital can hold a minimum of 2 electrons, each with opposite spins
97.

Who proposed that electrons are only found in specific, discrete circular orbits around the nucleus?

a)

Albert Einstein

b)

Erwin Schrodinger

c)

Ernest Rutherford

d)

Niels Bohr

98.

Who used theoretical calculations and experimental results to devise and solve a mathematical equation describing the behavior of the electron in a hydrogen atom?

a)

JJ Thomson

b)

Niels Bohr

c)

Erwin Schrodinger

d)

James Chadwick

99.

When atoms _____________ energy, their electrons move to higher energy levels. These electrons _____________ energy by emitting light when they return to lower energy levels.

a)

lose, absorb

b)

absorb, lose

c)

lose, lose

d)

absorb, absorb

100.

Which form of radiation has the highest frequency?

a)

radio waves

b)

ultraviolet

c)

x-ray

d)

gamma

101.

Heisenberg's Uncertainty Principle states that it is impossible to know both the ___________ and the __________ of a particle at the same time.

a)

velocity, position

b)

velocity, energy

c)

position, energy

d)

velocity, speed

102.
Which scientist developed the Quantum Mechanical
a)
E. Schroedinger
b)
W. Heisenberg
c)
J. Dalton
d)
N. Bohr
103.
An electron cloud
a)
represents a 50% probability of finding an electron
b)
has uniform density
c)
can be called an orbital
d)
can only show where the electron is not located
104.
The n quantum number gives information about
a)
Size and Energy of the energy level
b)
orientation of the orbital
c)
spin of the electron
d)
shape of the orbital
105.

What was wrong with the Bohr model?

a)

It was disproved by the gold foil experiment.

b)

It could only describe the emission spectrum of hydrogen.

c)

It could only describe the emission spectra of elements with more than one electron.

d)

It was disproved by the cathode ray experiment.

106.

Orbits in Bohr's model of an atom could be described as ...

a)

Specific circular paths around the Sun where planets are located

b)

Specific circular paths around the nucleus where electrons are located

c)

Areas around the nucleus where there is a high probability for electrons to be present

107.

Energy levels in Bohr's model of an atom could be described as ...

a)

Orbits with fixed energies where an electron moves around an atom

b)

Orbits with a wide range of energies where an electron moves around an atom

108.

An atom is

a)

A fundamental subatomic particle of all matter

b)

The smallest partcle of an element that changes its identity during chemical reaction

c)

The smallest partcle of an element that retains its identity during chemical reaction

109.

An electron is

a)

a negatively charged subatomic particle that almost 2000 times lighter than a proton and moves around the nucleus of an atom

b)

a positively charged subatomic particle that almost 2000 times lighter than a proton and moves around the nucleus of an atom

c)

a neutral subatomic particle that almost 2000 times lighter than a proton and moves around the nucleus of an atom

d)

a negatively charged subatomic particle that has the same mass as a proton and is located in the nucleus of an atom

110.

Ernest Rutherford was

a)

A physicist who proposed a model of an atom in which an electron is found only in specific orbits with fixed energies around the nucleus.

b)

A physicist who discovered the first subatomic particle - an electron, and demonstrated that an atom is divisible. Proposed Plum-Pudding model of an atom

c)

A physicist who performed Gold Foil Experiment and demonstrated that an atom is mostly an empty space and the nucleus of an atom is positively charged and contains most of the mass of an atom.

111.

Quantum is...

a)

Specific circular paths around the nucleus where electrons are located

b)

The amount of energy required to move an electron from one energy level to another energy level.

c)

Energy levels where electrons of an atom are located

112.

Who was Erwin Schrodinger?

a)

A physicist who proposed a model of an atom in which an electron is found only in specific orbits with fixed energies around the nucleus. An electron in the model needs to absorb or emit energy to move from one orbit to another

b)

A physicist who discovered the first subatomic particle - an electron, and demonstrated that an atom is divisible. Proposed Plum-Pudding model of an atom

c)

A physicist who performed Gold Foil Experiment and demonstrated that an atom is mostly an empty space and the nucleus of an atom is positively charged and contains most of the mass of an atom.

d)

A physicist who gave the foundation to quantum mechanical model of an atom. Intorduced a theory describing the behavior of an electron as a wave function.

113.

Which orbit has the lowest energy level in the Bohr's model of an atom?

a)

The orbit that is the fatherst away from the nucleus of the atom

b)

All orbits in the atom have the same energy

c)

The orbit that is the closest to the nucleus of the atom

114.

Choose limitations of Niels Bohr model of an atom. Choose ALL that apply

a)

Bohr's model didn't indicate where electrons are

b)

Bohr's model was proposed only for hydrogen atom, not for atoms with more than 1 electron

c)

Bohr's model considered an electron only as a particle

d)

Bohr's model considered an electron only as a wave

115.

WHhat is the difference between an orbit and an orbital?

a)

An orbit is a 3D probability cloud where an electron could be found, an orbital is a specific circular path of an electron

b)

An orbit and an orbital are the same things describing the location of an electron

c)

An orbit is a specific circular path of an electron, , an orbital is a 3D probability cloud where an electron could be found

116.
What did De Broglie work on?
a)
quantum theory
b)
nuclear chemistry
c)
uncertainty principle
d)
wave theory
117.
What did Planck work on?
a)
quantum theory
b)
nuclear chemistry
c)
uncertainty principle
d)
wave theory
118.
What is the currently accepted model of the atom?
a)
Solid sphere
b)
Nuclear
c)
Planetary
d)
Quantum Mechanical
119.

Which Scientist came up with the NUCLEAR model?

a)

Dalton & Democritus

b)

Rutherford

c)

Thompson& Milliken

d)

Heisenberg & De Broglie