Other+Scientists

Democritus
[] Summarize his theory of the atom. h=6.626068 × 10-34 J s; m=mass in kg; v=velocity in m/s ||
 * [[image:http://www.kentchemistry.com/images/links/atomic/dimg13.gif width="61" height="39" align="center"]]

Who were his critics and what theories were postulated to challenge his?

James Chadwick [] What did he discover and when? Why did it take so long to make this discovery
 * -James Chadwick discovered the Neutron in 1932. **
 * -It took James a long time to make this discovery because the research could not emerge until he came back from the war. **
 * -Atoms**
 * -Neutrons**
 * -Alpha Particles**

Louis DeBroglie [] Explain his contribution to the wave-particle duality theory. His contribution is that he found that the the equation for wavelength is: h=6.626068 × 10-34 J s; m=mass in kg; v=velocity in m/s || .
 * [[image:http://www.kentchemistry.com/images/links/atomic/dimg13.gif width="61" height="39" align="center"]]

Robert Millikan [] What is Millikan’s major contribution? Watch the video that animates the Oil Drop Experiment. Let’s pretend that you have to explain what happened in this experiment to a class of fourth graders. How did the experiment work and what did Millikan find out? You cannot use any big fancy words!!!
 * -Harvey Fletcher used the Oil Drop Experiment to find out the charges of the electrons, J.J Thompson used thier equations to find out the mass equations and mass of the electron. **
 * - They use droplets of oil that they place on a metal tray which is hooked up to a battery that controls the electricity of the two metal plates and once the oil droplets reach the little hole in the middle of one of the trays they increase the voltage of the plates and then a special box sends invisible rays towards the droplets which makes the oil droplets choose which charge they have. (negative or positive) **

Erwin Schrodinger and Werner Heisenberg [] The **Heisenberg uncertainty principle** states by precise inequalities that certain pairs of physical properties, such as position and momentum cannot be simultaneously known to arbitrarily high precision. That is, the more precisely one property is measured, the less precisely the other can be measured. Schrodinger used mathematical equations to describe the location and energy level of an electron. He developed the quantum mechanics model (the widely accepted atomic model today). He also proposed the wave theory of matter. In a series papers he describes his partial differential equation that is the basic equation of quantum mechanics and bears the same relation to the mechanics of the atom as Newton's equations of motion bear to planetary astronomy.

Figure (a) shows that electrons are located all throughout the entire cell and can be "found" just about anywhere. Figure (b) explains the density of the electrons in an atom. Most of which are found nearest to the nucleus. Figure (c) graphs electron density (Y2) is shown as a function of distance from the nucleus; (r) as a graphical representation of the same data used to generate figure b. Figure (d) is the total probability of finding an electron plotted as a function of distance from the nucleus (r).