Atomic Theory Scientists

Question 1

Democritus

Answer 1

Engaged in thought experiments → Start of the Atomic Theory

Question 2

Democritus

Answer 2

Proposed idea that all matter is composed of atoms (tiny particles).

Question 3

John Dalton

Answer 3

“The Father of Modern Atomic Theory”

Question 4

John Dalton

Answer 4

Inferred proportions of elements

Question 5

John Dalton

Answer 5

Proposed that Oxygen and Hydrogen are components of water

Question 6

William Crookes

Answer 6

First to discover electrons but had no explanation for it

Question 7

J.J Thomson

Answer 7

Discovered the Electron and explained it (found charge and mass)

Question 8

J.J Thomson

Answer 8

Showed that electrons were part of matter - the structure of the atom had mass

Question 9

J.J Thomson

Answer 9

“Raisins in Pudding”

Question 10

Ernest Rutherford

Answer 10

“The Father of the Nuclear Atomic Atom”

Question 11

Ernest Rutherford

Answer 11

Made improvements to the atomic model in regard to the characteristics of the nucleus and where the mass is found

Question 12

Ernest Rutherford

Answer 12

Discovered radiations could split into 3 types of beams with magnetic fields

Question 13

Ernest Rutherford

Answer 13

“The Gold Foil Experiment”

Question 14

Ernest Rutherford

Answer 14

Identified the Proton

Question 15

Henri Becquerel

Answer 15

Discovered Radioactivity

Question 16

Goldstein

Answer 16

Discovered Protons, but did not know what it is

Question 17

Chadwick

Answer 17

Discovered the Neutron

Question 18

Newton

Answer 18

Proposed that light was a particle

Question 19

Huygen

Answer 19

Proposed that light was a wave

Question 20

James Maxwell

Answer 20

Proposed that light is an electromagnetic wave

Question 21

Kerchhoff

Answer 21

Pioneered the field of the study of black bodies

Question 22

Max Plank

Answer 22

Studied “Black Bodies”

Question 23

Max Plank

Answer 23

Found a formula that treated light as if it was discrete, NOT continuous
(Treated the energy of the light in quantums of energy)

Question 24

Heinrich Hertz

Answer 24

Discovered the Photoelectric Effect

Question 25

Albert Einstein

Answer 25

Says light consisted of streams of Planck’s Quanta, and called them Photons

Question 26

Neils Bohr

Answer 26

Used Spectroscopy to understand spectral lines

Question 27

Neils Bohr

Answer 27

improvements to the characteristics of the electron

Question 28

Neils Bohr

Answer 28

Discovered bright line spectra (coloured lines) and absorption spectra (gases that absorb coloured lines) using gas discharge tube

Question 29

Neils Bohr

Answer 29

Suggested that light in discrete quantums are also only allowed certain energy levels

Question 30

Neils Bohr

Answer 30

only accurately predicts special line for only hydrogen

Question 31

Robert Bunsen & Gustav Kirchhofft

Answer 31

Developed Spectroscopy in 1859

Question 32

Werner Heisenberg

Answer 32

Discovered the Uncertainty Principle

Question 33

Erwin Schrodinger

Answer 33

Used (devised) the Wave Equation (Wave Mechanics) to determine the probability of finding an atom’s electrons at a particular point within an atom

Question 34

Lous De Broglie

Answer 34

First Proposed that matter (particles) could have wave-like properties

Question 35

Antoine Lavoiser

Answer 35

“Father of Modern Chemistry”

Question 36

Milikan

Answer 36

Eye drop experiment

Question 37

Aufbau

Answer 37

Principle - Electrons enter orbitals of lowest energy first

Question 38

Pauli

Answer 38

Principle - No two electrons in the same atom can have the same set of quantum numbers

Question 39

Hund

Answer 39

Rule - Electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with parallel spin. Then the second electron then adds to each orbital so that their spin is paired and opposite in direction.

Question 40

Atomos

Answer 40

the point of indivisibility

Question 41

Transmutation

Answer 41

Changing one substance into another

Question 42

Electromagnetic Spectrum

Answer 42

The range of frequencies (frequency of waves is continuous)

Question 43

Quantum

Answer 43

Energy from light in discrete/individual amounts/packets

Question 44

Photoelectric Effect

Answer 44

Radiation is shone on a metal and results in flowing energy

Question 45

Spectroscopy

Answer 45

When white light is passed through a prism, it splits into its component colours

Question 46

Spectral Lines

Answer 46

Occurs when the electron emits a quantum of energy in the form of light equal to the change in energy level

Question 47

Uncertainty Principle

Answer 47

It is impossible to know both the position and the momentum of an object beyond a certain measure of precision (mathematically proved)

Question 48

Orbital (Electron Cloud)

Answer 48

Region of space where the electron is most likely to be found Isoelectronic - Atoms which have the same electron arrangements