https://padlet.com/alhuang4/y0gn54ouh53yqryy Albert Huang's Timeline Project en-us 2020-12-04 14:54:03 UTC 2020-12-07 14:26:20 UTC hello@padlet.com alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/987743568 Democritus was a Greek philosopher and came up with the idea of tiny particles. This was the first idea of an atom and he called it Atomos, meaning indivisible. He thought that all of these particles were indestructible and could change size and shape depending on what it was creating. They were tiny indestructible particles.]]> 2020-12-04 14:56:42 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/987743568 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991965183 Aristotle completely disagreed with Democritus's idea of the atom and instead said that everything is made from just 4 elements, Air, water, fire and earth. Because Aristotle was a popular philosopher people believed him more than Democritus. This meant that no one investigated more about atoms for another 2000 years. ]]> 2020-12-06 18:36:13 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991965183 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991974539 Dalton was also known as the father of atomic theory because he started to think about the idea of an atom.  He theorized that atoms were too small to see and that they made up everything in the world.  He did lots of experiments to prove to the world that atoms were real. He also theorized that atoms of a certain element were the same, and that atoms of 2 different elements would be different from each other. ]]> 2020-12-06 18:42:44 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991974539 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991983824 Thomson was the first to discover that there were smaller particles that made up an atom. He discovered that there was a negatively charged particle and he called it an electron. He came up with the idea that there would be a positively charged substance and within that substance there would be negatively charged electrons scattered in like a cookie with chocolate chips. ]]> 2020-12-06 18:49:06 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991983824 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991995915 Rutherford did an experiment where he shot positively charged particles at some gold foil. What he saw was that some of the particles went through the atoms and some bounced off. He concluded that atoms had a positively charged center (the nucleus) with electrons orbiting it at a distance. He concluded that most of the atom is empty space because that is why some of the the particles went through the atoms. He also said that the nucleus is very tiny compared to the whole atom. The ones that bounced off must have hit the nucleus. ]]> 2020-12-06 18:57:38 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/991995915 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992197385 Bohr agreed with Rutherford and added to his model. He came up with the idea that electrons had certain energy levels. The electrons could go up an energy level if it had gained energy and it would move down if it lost energy. The electrons would orbit around the nucleus in a fixed path. The higher the energy level the farther away it would be from the nucleus. ]]> 2020-12-06 21:26:10 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992197385 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992217388 Chadwick discovered a new particle in the atom, the neutron. The neutron is a neutral particle, meaning it has no charge. Chadwick used wax to catch the particles and discovered neutrons. This was very important after Enrico Fermi shot neutrons at atoms and split them, and started the nuclear age. ]]> 2020-12-06 21:42:52 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992217388 alhuang4 https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992232093 Now the scientists slightly disagree with Bohr that electrons orbit in neat, perfect, orderly energy levels. Now scientists like Heisenberg think that electrons orbit around the nucleus billions of times a second and that they create a sort of cloud, not orbits. Electrons do not travel in perfect circles, creating the cloud because they orbit so fast. But the electrons still orbit based on the amount of energy it has. (The picture shows electrons, but the whole orange fuzz is where the electrons could be and is the cloud.) ]]> 2020-12-06 21:55:17 UTC https://padlet.com/alhuang4/y0gn54ouh53yqryy/wish/992232093