Ray H 3 timeline.

They developed the theory that all metals are composed of mercury and sulfur and that it is possible to change base metals into gold.
They broke down the chemical composition of the four basic elements at the time, Fire, Earth, Wind, and Water, and that eventually evolved into The Periodic table used today. Alchemy contributed to the Atomic Theory by laying down the foundation of the Modern Day Periodic Table of the elements.

Studied mathematics, geometry, geology, astronomy + religion
Solar System Model
Introduced the atomic theory where geometric forms were the shape of atoms, according to which atoms broke down mathematically into triangles, for example: fire (tetrahedron), air (octahedron), water (icosahedron), and earth (cube). He postulated that a fifth atomic type must exist, which Aristotle later called `ether,' and the heavens, and objects in the heavens (stars, planets, Sun), are composed of atoms of ether.

Schools/Studied - Pre-Socratic philosophy, Atomism, Materialism
Promulgated the atomic theory, which asserted that the universe is composed of two elements: the atoms and the void in which they exist and move.

Studied at Plato's Academy
He laid the philosophical groundwork for all subsequent discussions of elements, pure substances, and chemical combination. He did not believe in the atomic theory and taught so otherwise. He thought that all materials on Earth were not made of atoms, but of the four elements, Earth, Fire, Water, and Air. He believed all substances were made of small amounts of these four elements of matter.

College degree
Performed some of the earliest experiments with gases. As a chemist, he helped separate the science of chemistry from its roots in alchemy and is sometimes known as the father of chemistry because of this. Created Boyles law and it expresses the inverse relationship that exists between the pressure and volume of a gas, and it was determined by measuring the volume occupied by a constant quantity of air when compressed by differing weights of mercury.

Bachelor's degree, law degree
Found that the total mass of products and reactants in a chemical reactions is always the same. This led to the theory of the law of conservation of mass. He reacted oxygen with inflammable air, obtaining "water in a very pure state." He correctly concluded that water was not an element but a compound of oxygen and inflammable air, or hydrogen as it is now known. To support his claim, Lavoisier decomposed water into oxygen and inflammable air.

Doctorate of Laws, math + philosophy tutor at New College in Manchester
Solid Sphere of Billiard Ball Model
Proposed all matter was composed of atoms, indivisible building blocks. Believed atoms of different elements could be universally distinguished based on their atomic weights. Discovered that oxygen combined w/ one or two volumes of nitric oxide in closed vessels over water and this observation of integral multiple proportions provided experimental evidence for his atomic ideas.

Education in science, master's degree, studied for two years at the University of Heidelberg
Devised the periodic classification of the chemical elements, in which the elements were arranged in order of increasing atomic weight. He basically created the periodic table. This table made it possible to predict properties of elements that had not yet been discovered. He noted gaps in the table and predicted that then-unknown elements existed with properties appropriate to fill those gaps.

Doctorate in physics, appointed professor of physics at the University of Bonn
This effect was discovered by Heinrich Hertz while he was performing experiments that led to the discovery of electromagnetic waves. It confirms that electromagnetic radiation is related to the atomic structure of an element because the wavelength determines how many electrons are emitted. Electrons surround the nucleus of an atom, which corresponds to the atomic structure of that atom.

Scholarship at Trinity College, B.A. degree in mathematics
His experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup." He discovered the electron and then went on to propose a model for the structure of the atom. His work also led to the invention of the mass spectrograph.

Marie Curie - Masters degree in Physics and degree in mathematics
Pierre Curie - Doctor of Science degree
Marie Curie conducted her own experiments on uranium rays and discovered that they remained constant, no matter the condition or form of the uranium. The rays, she theorized, came from the element's atomic structure. This revolutionary idea created the field of atomic physics. Marie and Pierre Curie discovered the radioactive elements polonium and radium.

Honorary doctorate degrees in science, medicine and philosophy
Mathematically proved the existence of atoms. Atomic theory says: any liquid is made up of molecules. He reasoned that if tiny but visible particles were suspended in a liquid, the invisible atoms in the liquid would bombard the suspended particles and cause them to jiggle because the English botanist Robert Brown noticed that pollen seeds suspended in water moved in a strange "swarming" motion.

Doctorate degree
He called the packets of energy quanta and he was able to determine that the energy of each quantum is equal to the frequency of the radiation multiplied by a universal constant that he derived, now known as Planck's constant. He postulated that the energy of light is proportional to the frequency. His work led to Albert Einstein determining that light exists in discrete quanta of energy, or photons.

Bachelor's degree in the classics, doctorate in physics
Accomplished the design and fine-tuning of experiments that confirmed the most important scientific theories of his time, providing the implications for atomic theory. His oil drop experiment confirmed the existence of the electron and determined its charge. There was a theory that electricity was conveyed by a miniscule unit, the electron, that gained acceptance. He succeeded in precisely determining the magnitude of the electron's charge

Bachelor of Arts and Master of Arts degrees, first-class honors in math and science
He postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. He demonstrated that the atom has a tiny and heavy nucleus using his gold foil experiment. Rutherford designed an experiment to use the alpha particles emitted by a radioactive element as probes to the unseen world of atomic structure.

Master’s degree in Physics Doctor’s degree
Proposed a theory for the hydrogen atom based on the quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and If electrons jump to a lower-energy orbit, the difference is sent out as radiation.

Bachelor's degree
He used self-built equipment to prove that every element's identity is uniquely determined by the number of protons it has. His discovery revealed the true basis of the periodic table and enabled Moseley to predict confidently the existence of four new chemical elements, all of which were found. He also argued that atomic number is a better indicator of an element's chemical properties than atomic weight

Got doctorate at University of Vienna
Electron Cloud Model
Assuming that matter (e.g., electrons) could be regarded as both particles and waves, he formulated a wave equation that accurately calculated the energy levels of electrons in atoms. It came as a result of his dissatisfaction with the quantum condition in Bohr's orbit theory and his belief that atomic spectra should really be determined by some kind of eigenvalue problem.

Studied physics and mathematics, earned a doctorate
He contributed to atomic theory through formulating quantum mechanics in terms of matrices and in discovering the uncertainty principle, which states that a particle's position and momentum cannot both be known exactly. This theory and the applications of it resulted in the discovery of allotropic forms of hydrogen.

English physicist, earned a B.S. and MSc
He discovered the neutron, a particle with no electric charge that made up the nucleus of an atom with protons. He was convinced that alpha particles did not have enough energy to produce such powerful gamma-rays. He performed the beryllium bombardment experiments himself and interpreted that radiation as being composed of particles of mass approximately equal to that of the proton but without electrical charge—neutrons.