This exercise refers to identifying elements AX and BX. You may use the measurement widget but do not "publish to global view". Just use that to record the wavelengths which you can then later put in your email document. To the right is an example screen shot for element AX showing the 4 spectral lines (wavelengths omitted) that you would need to match up with the periodic table of elements. The white line at the top labelled 4105/0 is what you slide up up and down to measure the wavelengths of the 4 dark lines. Your response to this question should include

• the wavelengths of the identified lines in AX and BX.
• Which element in the periodic table that you think corresponds to AX and BX (remember, AX and BX both are elements with atomic numbers less than 20)

Refer to the left diagram and answer this series of questions:

a) What possible values of photon energies can this atom "emit" if the electron is moved to the highest energy level shown in this diagram.




b) If an incoming photon has energy = 9 units and the electron is in the ground state (as pictured), what will happen to the incoming photon and the electron?



c) if the electron is in the first excited state (e.g. energy level =5) and in incoming photon of of energy = 5 units hits the atom, what will happen to that photon and the electron?

Supposed we move our Sun to a distance of 10 Light Years away from the Earth. We image the sun with a digital detector and measure a received flux of 100 units (these are arbitrary flux units - AFUs). Show your work or reasoning on the following 3 questions.

• If we now moved the Sun to a distance to 20 light years, what would the received flux now be (in units of AFUs).

• We observe a new star with properties exactly like the sun so we can assume that its intrinsic luminosity is exactly like the sun. The received flux from this new star is 1000 AFUs. What is the distance to this newly discovered star (in units of Light Years)?

• Finally we observe another new star, a red one. We know that the distance to this newly discovered red star is 10 Light Years. We observe a flux of 500 AFUs from this star. What is the luminosity of this star, compared to the Sun?