8000 BC

Evolving theories of Matter Timeline.

By Kevin Olafson

Niels Bohr

John Dalton

Hantaro Nagaoka

Robert Boyle

Stone Age Chemists.

Quantum Theory

These chemists lived before 8000 B.C. In an area called the Middle East. This is the stone age because they just used simple stone tools. Metals have not been discovered yet. Once these chemists learned how to start and control fires. This helped them to change materials to their advantage. They could cook foods and hardened mud bricks.

In 1922 Bohr suggested that electrons do not orbit randomly but they move in specific circular orbits or electron shells. This is kind of like our planets orbitint the sun. Electrons jump between these shells by gaining or losing energy. He ended up winning the nobel Prize in physics in 1922.

In 1904 Nagaoka made his own model of the atom. The atom was resembled like a miniature solar system. At the center of the atom was a large positive charge kind of like the sun. The negative electrons orbited around this charge kind of like the planets that orbit the sun.

In 1660 Robert Boyle experimented with behavior of gases. He was interested to what happened when gases were under pressure. Through lots of tests Boyle found out that matter is made out of many many particles. He believed that the tiny particles would group together in different ways to form individual substances. He thought that the purpose of chemistry was to determine the types of particles made up in the substances.

In 1808 Dalton suggested that matter was made up of elements. He was the first scientist to identify an element as a pure substance. Some of the famous substances he found were gold, chlorine and oxygen. He also put forward the first modern theory of atomic structures. He said that each element is composed of a particle called an atom. All atoms in a element are identical in mass, and no two elements have the same atom mass. All oxygen atoms have the same mass but they are different from the chlorine atoms.

The Quantam Theory is a modern day theory. There are 5 main parts of the Quantum theory. 1.Energy is not continuous. 2.Elementary particles behave like particles and waves. 3.The movement of these particles is inherently random. 4.It is physically impossible to know both the position and the momentum of a particle at the same time. 5.The atomic world is nothing like the world we live in. Niels Bohr said that anybody that does not understand what quantum theory is shocked.

Today

8000 BC

James Chadwick

Ernest Rutherford

Joseph Thomson

Antoine Lavoisier

Democratis and Aristotle.

In 1908 Ernest Rutherford won the Nobel Prize for his work in radioactivity. He suggested that atoms were mainly empty spaces through which positive particles could pass, but at the core was a tiny positively charged center. This he called the nucleus which is pretty much the brain of the cell.

Refined Bohrs model . He discovered the nucleus contained positively charged particles called protons and neutral particles called neutrons. The neutron has about the same mass as the proton but carries on electrical charge.

Were both greek philosipher. Demotcratis came up with the word Atomos which means indivisible. He stated that each type of material was made up of a different type of atomos. These different particles he believed gave each materials its own unique set of properties. By mixing different atomos you could make new materials with their own unique properties. Some people didn't believe this because of another greek philoipher who name was Aristotle. He stated that everything was made up of fire, water. air and earth. Everyone believed Aristotle more but looking back on it Democratis was more right then Aristotle.

In 1770 Antoine Lavoisier started to studied chemical interactions. By 1780s he had made a system for naming chemicals. This was important because all scientists could make observation and use the same words to describe. Using the system he found out chemicals like hydrogen, oxygen and carbon. He is called the father of chemistry. Sadley in the french revolution he chose the wrong side and got his head chopped off. After he died his wife Marie carried on his work.

In 1897 Thomson was the first person to discover the subatomic Particle. Through his research and studies he found out about the subatomic particle. He believed that negatively charged particles were part of atoms. He said that it was kind of like raisins in a bun.

Aristotle

Democratis