M1U1 Timeline

Question 1

Enumerate the 7 Atomic Theories and its dates

Answer 1

1. Atomism (442 BC)
2. Aristotle Model (300 BC - Early 1800s)
3. Solid Sphere Model (1803)
   Hook and Eye Affair Model (1803)
4. Plum Pudding Model (Late 1890)
5. Nuclear Model (1911)
6. Miniature Solar System/ Planetary Model (1913)
7. Modern Atomic Theory: Quantum Mechanical Model (1926)

Question 2

When and who discovered electrons?

Answer 2

1897, Joseph John Thomson

Question 3

When and who discovered protons?

Answer 3

1919, Ernerst Rutherford

Question 4

When and who discoveerd neutrons?

Answer 4

1932, James Chadwick

Question 5

Who were the ones to propose Atomism?

Answer 5

ancient Greek philosopher Democritus and Leucippus

Question 6

What does the theory of Atomism state?

Answer 6

All matter is composed of indivisible elements called atoms.

Question 7

Wha tare atoms according to democritus?

Answer 7

Atoms were small, hard particles made of the same materials, but formed into different shapes and sizes

Question 8

According to Aristotle Model, what was the four elements/ substance of matter?

Answer 8

Fire, Air, Water, Earth

Question 9

According to Aristotle Model, what was the four properties/ essences of matter?

Answer 9

Hot, Cold, Dry, Wet

Question 10

He proposed a model as an attempt to describe the structure of the atom?

Answer 10

John Dalton

Question 11

What was John Dalton’s profession when he proposed a theory in 1803?

Answer 11

an English school teacher

Question 12

How are atoms described according to the Solid Sphere Model?

Answer 12

Atoms are tiny, indesctructible spheres with no internal structure

Question 13

It is a theory that matter is simply composed of atoms of different weights and is combined in ratios by weight. It is also proposed that these atoms are spherical and are in motion

Answer 13

Solid Sphere Model

Question 14

Describe the Hook and Eye Affair Model

Answer 14

Matter is made of tiny particles which is imagined to be little balls that are arranged in different combinations to make different things.

Question 15

What became the basis for television?

Answer 15

a primitive cathode ray tube

Question 16

When and who constructed a primitive cathode ray tube?

Answer 16

1870, Sir William Crookes

Question 17

When and who theorized that radioactive particles cause atoms to break down whihc then releases radiation?

Answer 17

1898, Pierre and Marie Curie

Question 18

What did Pierre and Marie Curie theorized?

Answer 18

Radioactive particles cause atoms to breakdown, releasing radiation that takes the form of energy and subatomic particles.

Question 19

Describe the atom as proposed by the Plum Pudding Model

Answer 19

the atom is composed of a positively charged sphere with negatively charged electrons distributed throughout it

Question 20

Who proposed the Plum Pudding Model?

Answer 20

Joseph John Thomson

Question 21

Why is it said that atoms are electrically neutral?

Answer 21

Because the positive and negative charges together would balance the two things so that the atom would become electrically neutral

Question 22

When and who discovered the quantum theory?

Answer 22

1900, Max Planck

Question 23

What does the quantum theory state?

Answer 23

Electromagnetic energy could only be emitted in quantized form

Question 24

Plank’s quanta are now called what by physicists?

Answer 24

Photons

Question 25

How was electrons discovered?

Answer 25

Using properties of Cathode rays

Question 26

Together with JJ Thomson, he discovered that there must be some positive charge somewhere

Answer 26

William Thomson

Question 27

When and who created special and general theories of relativity, and hypothesized the particle nature of light?`

Answer 27

1905, Albert Einstein

Question 28

This measures the charge of a single electron and is one of the fundamental physical constants.

Answer 28

elementary charge

Question 29

When and who measured the charge of a single electron?

Answer 29

1908, Robert Millikan

Question 30

elementary charge = ?

Answer 30

1.602 x 10^(-19)

Question 31

He developed the theory for the structure of the atom

Answer 31

Ernest Rutherford

Question 32

What was Ernest Rutherford known as?

Answer 32

Father of Nuclear Physics

Question 33

What does the nuclear model propose?

Answer 33

Proposed that most of the mass of the atom is contcentrated in tiny, positively charged nucleus at the center, with negatively charged electrons around it.

Question 34

Using this experiment, Rutherford observed the scattering of alpha particles and demonstrated for the first time, the existence of the atomic nucleus

Answer 34

gold foil experiment

Question 35

What is a nucleus according to Ernest Rutherford?

Answer 35

It is the small, dense, positively charged center of an atom

Question 36

Developed the Miniature Solar System/ Planetary Model in 1913

Answer 36

Niels Bohr

Question 37

What was Bohr's atomic model about?

Answer 37

Electrons travel in orbits around the nucleus, and chemical properties are determined by how many electrons are in the outer orbits

Question 38

Bohrs also integrated Planck quantum theory which states that ---

Answer 38

when an electron changes orbit, it emits a quantum of discrete energy

Question 39

What did Rutherford's scintillation detector detected when a beam of alpha particles was shot into air?

Answer 39

Hydrogen nuclei

Question 40

Aside from Rutherford, who was credited for the discovery of protons?

Answer 40

Eugene Goldstein

Question 41

Who and what what discovered in 1926?

Answer 41

Erwin Schrödinger, Modern Atomic Theory: Quantum Mechanical Model

Question 42

What are the two other terms for Erwin Schrödinger's Modern Atomic Theory: Quantum Mechanical Model

Answer 42

Quantum Chrynodynamics Electron Cloud Model

Question 43

What was Schrödinger's finding?

Answer 43

Electrons do not orbit but move at high speeds in an electron cloud around the nucleus.

Question 44

What does electrons do in an electron cloud according to Schrödinger?

Answer 44

In an electron cloud, electrons whirl around a billion times in one second in a random pattern.

Question 45

What component of the atomic nucleus was discovered in 1932?

Answer 45

Neutron component

Question 46

The discovery of netron explained what?

Answer 46

nuclear fission of uranium 235; this also made it possible to produce elements heacier than uranium in the lab

Question 47

When and who discovered the nuclear fission?

Answer 47

Otto Hahn and Lise Meitner

Question 48

What was Otto Hahn regearded as?

Answer 48

Father of Nuclear Chemistry

Question 49

What were discovered in 1951?

Answer 49

Glenn Seaborg discovered: - transuranium elements - advances in nuclear medicine including develoopment of I-131 for thyroid disease

Question 50

When and who proposed the quark model?

Answer 50

1964, Mann

Question 51

What does the quark model describe?

Answer 51

Describes elementary particles that have no substructure (and therefore can't be split)

Question 52

These three along with many other scientists said that electrons do not orbit the nucleus in neat planet-like orbits but move at high speeds in an electron cloud around the nucleus. (1926- 20th Century)

Answer 52

Schrodinger, Heisenberg, Einstein

Question 53

People under the medieval period

Answer 53

Democritus Leucippus Aristotle/Empodecles