Names: ______Atomics Web-Quest

Directions: Google “phet” and choose the subtitle ‘chemistry.”

1. Scroll down and choose “Rutherford Scattering.” Click on “Plum Pudding Atom,” click the alpha particle button, and observe how alpha particles behave when subjected to the model. Explain your observations:

2. Go back to “Rutherford Scattering” but choose “Rutherford Atom.”

a. Choose the energy level option (top option on left side). Before starting the simulation, make observations about the distances between the nucleus and energy levels in the atoms. Explain your observations:

b. Click the alpha particles button to start the simulation. Observe how the alpha particles interact with the atoms and specifically the nucleus. Explain your observations:

c. Choose the atomic view option (second option on left side). Set the atom (on right) to the lowest values of protons and neutrons. Which element are you studying? Write the isotopic notation:

d. Click the alpha particles to start the simulation. Observe how the alpha particles interact with the atom and the nucleus (the entre box shown is the atom now). Explain your observations:

e. Change the atom (on the right side) and observe the alpha particles interactions with the new element. Are there any similarities or differences? Explain your observations:

3. Go back to the home chemistry screen and choose “Isotopes and Atomic Mass.” a. Choose the “Isotopes” option. The simulation starts with the H-1 atom. Open the “Symbol” and “Abundance in Nature” boxes. Observe the changes as you add a neutron to the atom. What happened to the symbol, mass number, and abundance in nature?

b. Can this action of adding a neutron to an atom be done in our lab? Explain:

c. Choose new elements on the periodic table. What happens to the stability and abundance in nature of the atoms when neutrons are added in each atom?

4. Go back to the simulation but choose the “Mixtures” option.

a. Open the “Percent Composition” and “Average Atomic Mass” boxes on the right. Starting with Hydrogen, make a mixture of H-1 and H-2. Write observations about what happens to the Average Atomic Mass when H-1 is added versus when H-2 is added.

b. Choose the option “Nature’s Mix’ on the bottom of the screen. If you pulled one atom of Hydrogen out of a natural sample, which isotope will you probably pick?

c. Choose Helium. If you pulled one atom of Helium out of a natural sample, which isotope will you probably pick?

d. Choose Beryllium. What is interesting about Beryllium’s isotopes?

e. Do all elements have the same number of isotopes? Provide examples to defend your answer. f. Choose Sulfur. Why is the Average Atomic Mass of sulfur so low when there are isotopes with higher mass numbers?

g. Choose Carbon. Show a calculation using the evidence in the simulation, to prove that Carbon’s Average Atomic mas is 12.010701amu.