Possible humanitas project...

http://www.charitywater.org/whywater/ <---Check it out :), while it may not directly affect our community, it is a huge ordeal in the global one.

Atoms Throughout the Ages

I posted this picture back in September, and now I am about to finish what I started.

Jesseca M. Kusher

Teacher S. Harrelson

4^th Period Science

12 December 2010

The Atom Models Throughout the Ages

Since the beginning of time mankind has always questioned the world and its surroundings. It has questioned everything from lightning to nanotechnology, and because of these questions mankind has evolved to become an incredibly intelligent species. Yet we still have flaws in our answers, and we probably will always question the answers we have. This process of question asking can be considered one of mankind’s greatest accomplishments; the scientific method. Through the scientific method mankind has come far. One example of how the scientific method has helped scientists throughout the ages achieve greatness is the way the model of the atom has adapted and changed with the input and thought of many generations.

Back many centuries ago, before the scientific method was created a single man broke the status quo and strayed from the path of mythology; Democritus. Democritus lived around 430 B.C.E. and was the first person to think theoretically about the scientific qualities of life and nature without attributing them to a mythical being or phenomenon. Democritus went along to create a name for one of the smallest building blocks of matter. Democritus decided to call the smallest form of building block to be called an atom because atomos meant uncuttable in Greek. So at this point the scientific method had reached no farther than the hypothesis stage, and the atomic model had gotten no further than a name; but as the scientific method grew and more steps were added so did the atomic model.

Centuries later the scientific method stood steady as a rock. One by one scientists took their spot in the limelight with their new atom models. First John Dalton took the stage, and with him he brought a pool-ball-like model. Next came J.J. Thomson in 1897 with a muffin-like-model where positive and negatively charged particles where like berries inside of a muffin; thus thoroughly scattered. Latter on in 1911 Ernest Rutherford claimed his five-minutes-of-fame with his creation of the “peach pit” model in which the center was positively charged and the “flesh” surrounding it was negatively charged. Only two years later in 1913 Niels Bohr took the stage with a model unlike all of the ones previous, an onion model. His model had a nucleus like Ernest Rutherford’s model, but it also had little particles called electrons that orbited the nucleus in orbitals. Soon afterwards in 1932 James Chadwick built on to the onion model to conclude that it was made up of tiny particles called protons and neutrons. Finally after centuries of hard work the atom model stands on stage with Erwin Schrodinger who still stands there with his “cotton candy” model where the electrons orbit the nucleus in a strange cloud where they are constantly popping in and out of existence.

After having had changed for centuries now, twenty years from now another scientist will take the stage. The model of the atom has been evolving for centuries now, and it is not done yet. With the production of new technology and the work of many scientists the model of the atom we have now will someday be looked back upon in the same way we see Dalton’s now. The people of the future will look back at it and think, “What were they thinking?” The people will laugh at our basic scientific understanding of the world and its surroundings. A least our generation of scientists will not be the first or last to be replaced upon the stage of science by another more intellectually evolved thinker than ourselves.

Overall mankind and its model of the atom have come far. It still has a long way to go, but mankind has come far. Imagine that only a few centuries ago lighting was attributed to Zeus, a Greek god. Now science has traveled from pure speculations to speculations with data created via experimentation. From the beginning of time mankind has questioned life, and now some answers unfold themselves, now the model of the atom looks like a lump of cotton candy; whether this is the truly idealistic model of an atom or not only time can tell. Time and the scientific method will help yet another generation of scientists achieve greatness.

How do we know about electrons if they are so tiny?

First of all that's a great question. How do we know about electrons if they are so tiny and small? We had to have discovered them at some point in history in order to know about them now; but when? And how? What experiments were tested to come to the conclusion that there are many little negatively charged particles buzzing around an atom?

To explain this simply, we know about electrons because of protons.

To explain not-so-simply:

Ever since J.J. Thomson's model of the atom back in 1897, probably even before that, scientists have known that atoms have to be composed of negatively and positively charged particles. In Thomson's model the particles were scattered throughout the atom's mass in a random order like berries in a berry muffin. Later on Rutherford speculated that the nucleus of an atom is positively charged (and he remains to be proven wrong) while the matter surrounding the center is negatively charged. While he was correct in both cases he was still missing the vital fact that the negative matter surrounding the center is moving. The particles surrounding the nucleus are electrons. Electrons pop in and out of the shells that they orbit inside of around the nucleus at random. One minute they are there, the next they could be across the universe for all we know. (That just shows you haw limited our knowledge of the universe is.) Anyway after Niels Bohr James Chadwick changed the atom model forever with his amazing addition; the the neutron.

So by knowing that the nucleus is positively charged and by knowing that atoms are normally neutrally charged we must conclude that a particle such as the electron must exist in order to balance out the electromagnetic charge.