The history of the atom timeline.

An ancient Greek philosopher named Democritus provided a theory that atoms existed. He stated that matter was made of small, hard particles that he called “atomos”. But Democritus does not have any proof that atoms existed, it seemed like to a lot of people it didn’t exist. Democritus did not do any experiments since he was a philosopher not a scientist.
How did Democritus come up with this theory without proof?
What did he think that atoms are used for?

Aristotle's theory was only based on the four elements fire, water, earth and air. Aristotle did not agree with Democritus's theory at all he believed that there were no particles that were separate, it was all one whole. Since Aristotle was more popular, his theory was left for 2000 years. Aristotle was a philosopher not a scientist so he did nothing to prove his theory was true.
How did Aristotle know that it is based on only four elements?
How did he become so popular to persuade his theory?

types of metals making it into ‘philosophical mercury’.This makes a liquid for protecting the seed of gold. After grinding the mercury with different substances, boiling, distilling several times and heating. Then it is mixed with a small part of gold. It is put into a flask, sealed and then heated. There is a treelike structure made out of mercury and gold in flask. (see the picture)
How do you get a philosopher stone?
How does spirituality and belief help with the science?

The main alchemist’s goal is the existence of the Philosopher's stone. The Philosopher’s stone could turn the most basic metals into the higher prized metal e.g (silver and gold). Alchemy practices are associated with magic, mythology, religion and spirituality. Alchemy is a protoscience (unscientific field of study and then becomes science later on) and some basic lab skills originate from alchemists.
One of the alchemist experiments is that you take normal mercury and distill it from different

Antoine identified the four elements by their physical properties. The elements are fire, water, earth and air. His work contributed mostly to the study of combustion. Antoine discovered and proved the theory that oxygen (he called) was made up in air. Antoine did not associate with atoms but he did discover the law of conservation of mass. Philosopher Joseph Priestley used his experiment of mercury calx heated and then collecting the gas 'pure air' was pure enough to breath. But Antoine

repeated Joseph's experiment, he came to the come to the conclusion that air is not one substance.It is several components.
Why did Antoine work with Joseph Priestley's experiments?
How did he come up with the name oxygen?

Joseph Proust discovered the laws of definite proportions or ( law of constant composition). This law is about a compounds that have the exact proportion of an element by the mass and it does not matter how the compound was made. His experiment was that any chemical compound has always have the same ratio of elements weight (mass).
Why was Joseph Proust inspired to study atoms?
How did his discovery changed his life? Did it make it better or worse?

John Dalton was a school teacher who performed a lot of experiments on atoms.He thought that atoms were like extremely small solid balls. Dalton's 4 statements were:
- Atoms are extremely small, not seen particles
- Atoms of one element are all the same
- Atoms of different elements are different
- Compounds form by merging atoms
His experiment on gases helped him discover the principle known as Dalton's law of particle pressures.
Why did he have an interest in atoms?
Why did he choose this job?

J.J Thompson was the person that shown that the atom was made of smaller things. He also determined that there was an existence of a positive particle in the atom and electrons. J.J Thompson's model is known as the "raisin bun model". His experiment was on Cathode Ray Tubes (CRT).The CRT were used in older bulkier televisions. This experiment helped discover electrons.
Is the CRT a main part of the television or minor?
What else would the CRT be used for in daily life?

Rutherford discovered that protons are positively charged particles that are in the centre.The centre is called the nucleus which is the centre of the atoms and the outside of the around the nucleus is mostly empty space.Rutherford's experiment is where a radioactive material release a beam of positively charged particles through the gold foil onto the screen. The particles mostly went through the gold and some were deflected.
What made Rutherford experiment on atoms?
How did Rutherford's help?

Niels Bohr continued on Rutherford's model. He suggested that electrons move around in layer or shells around the nucleus. All atoms have a certain number of electron shells around them. His experiment was baed on a hydrogen atom using a quantum theory. The theory was that energy was moved in only definite amounts & electrons jump from one orbit to another that has lower light energy a light quantum is released.
How did he survive in Denmark if there was a war?
How did his research help the war?

James Chadwick discovered neutrons. When he was working with Ernest Rutherford he found out about the particles with no charge and neutrons are found in the nucleus. James Chadwick discovered it using the scatter data to find the mass of a neutron particle.
Why did it take so long to discover a neutral particle?
What did James Chadwick do when working with Ernest Rutherford?