Describe another model in science that you have learned about that you think may have been revised over time as scientists have gathered new evidence.
Answers
Answer:
These are the notes (and diagrams) I use when I teach the atomic nature of matter to non-science majors. The best thing about this story is that it is a great example of science. Science (or scientists) build a model. If new evidence comes along, the model gets changed
Explanation:
Greek Model of the Atom
It always has to go back to the Greeks, doesn't it? Well, they did do a lot of stuff. I know they were really scientists but it is still a good place to start. Here is a picture of bust of Democritus.
In real life, he probably had color. Democritus is credited with coming up with the atom. The question was, what would happen if you keep taking something (like a tree) and breaking into smaller and smaller pieces? Would it always be a piece of a tree? Could you keep breaking it into smaller and smaller pieces? Democritus said that if you keep breaking it down, you would get to a size that could no longer be broken. This would be the indivisible piece. In Greek, atomos = indivisible. Thus, the atom. (I know there is more to the Greeks, but I need a place to start)
Dalton's Model
I am not going to go into the experimental evidence for Dalton's model of the atom, it's good stuff though. Let me just state what Dalton said:
Stuff can be broken into elements (the things listed on the periodic table).
Elements are atoms with different masses.
Compounds are a combinations of elements. You know, like water, salt or pizza.
Basically, Dalton just expanded on the Greek idea of the atom. An atom is a small things, and there are different masses with different properties.
J. Jonah Jameson Thomson - (AKA J.J.)
Thomson played with cathode rays. These are just beams of electrons (but cathode ray sounds cooler). By having the beam interact with electric and magnetic fields, Thomson was able to determine the mass to charge ratio for an electron. So, from that he knew that the electron came from the atom, it had a negative charge and a small mass. Here is the model that he proposed.
Thomson took the idea of the atom and tried to incorporate the evidence for the electron. In this model, the electrons are the small things and the rest of the stuff is some positive matter. This is commonly called the plumb pudding model because the electrons are like things in positive pudding.
Rutherford Scattering
Ernest Rutherford said one day "hey, I think I will shoot some stuff at atoms." I am sure his wife said "oh, Ernie" (she probably called him Ernie) "if it makes you happy to play with your little physics stuff, go ahead. I know how much you like it." So he did. He shot some alpha particles (which are really just the nucleus of a helium atom) at some really thin gold foil. Here is a diagram of his experiment.
I HOPE ITS USEFUL TO YOU
Answer:
These are the notes (and diagrams) I use when I teach the atomic nature of matter to non-science majors. The best thing about this story is that it is a great example of science. Science (or scientists) build a model. If new evidence comes along, the model gets changed
hope it is helpful\(￣︶￣*\))