1. Max Planck's hypothesis was that energy is released or absorbed in small packets called photons and that only certain energy values are possible. He also said that Energy(E) is equivalent to Frequency(v) multiplied by a Constant(h). This helped Bohr with his model of the atom because, in Bohr's model of the atom, electrons orbit the nucleus in specific pathways that have specific energy levels. There are only certain energy levels that an electron can travel in. Shown below is a picture of Bohr's model with Planck's equation next to it. It shows the different levels that electrons can travel on. Personally, I can compare this to a radio. You aren't able to pick up certain stations, so you can only be on specific stations when you're in a certain area. Just like there are only specific levels that the electron can be on in certain atoms.
2. JJ Thomson's Plum Pudding Model said that atoms were like plum pudding. The pudding part represented a positively charged section of the atom and there were little chunks of negatively charged electrons floating around. This was discovered using that Cathode Ray Tube Experiment which helped Thomson determine that there were negatively charged particles in atoms. The Plum Pudding Model was discarded due to the Gold Foil Experiment which revealed that an atom is mostly made up of empty space. The next experiment used was the Millikan Oil Drop Experiment which helped to determine the mass and charge of single electrons. This led to the Rutherford Model of the Atom. Rutherford's model was that there is a positively charged center and there are electrons orbiting randomly around the center. This was discarded because scientists reasoned that, in this hypothetical model, electrons would lose energy and crash into the positively charged nucleus. Thus came the Bohr Model which, as stated previously, came into being with the help of Max Planck's hypothesis that energy is released or absorbed in small packets called photons. The Bohr Model shows a positively charged nucleus with electrons orbiting around it in specific, neat paths with specific amounts of energy. The Bohr Model wad discredited because there was no possible way to determine the orbit of an electron so therefore the speed and position bust be random. After this, the Wave Model was hypothesized. In this model, there is a small, positively charged nucleus with electrons moving about in orbitals. This model also suggested that electrons release waves as they move. Part of this model was discredited when Henry Moseley discovered the Atomic Number which suggested that there was something missing. James Chadwick then discovered the neutron- a positively charged subatomic particle that's about the same size as a proton. Shown below are the first and the current models of the atom. You can see there is a lot that has changed since the first discovery of the atom. I remember learning about this in physical science my freshman year. We didn't go very in depth, but the basic knowledge I learned then has made it easier for me to remember how the model of an atom has developed.
3.When electrons are excited, they can jump to a higher energy level on an orbital. Then when these electrons fall back down a level, they emit a light. How many levels they drop and where they drop from is what determines which color is emitted. Not all colors are possible for every element since, according to Planck's Theory, electrons can only orbit on certain energy levels depending on the atom. When we broke the light-savers, the light emitted was not continuous because the electrons were not continuously being excited. They were only excited when energy was given to it when it was broken. After the electrons fell back down and emitted light waves, there wasn't more energy for them to repeat this unless we would break them again. There are many ways to apply this to my life since everyone uses light throughout their day. The electric bill itself is evidence that it takes energy to produce light. Or if I were to leave the lights on in my car, the battery would probably be dead by morning because the light is caused by energy.
