1. If 5 grams of A combine with 10 grams of B to make compound AB, how many grams of A would be needed to make compound A 2 B?  5  10  15  None of the above?

2. T or F All oxygen atoms have the same mass?  False. Because different oxygen isotopes exist, some will be O-16, O-17, and O-18.  Which is most prevalent?  How do you know?

3. In Thomson’s experiment, what is the effect of having more gas in the tube?  The more gas in the tube, the less the glow was at the end of the tube, and more the glow was in the middle of the tube.

4. What is a cathode ray?  A stream of electrons

5. Draw an atom, label the parts

6. Complete the table below ProtonNeutronElectron Location Approximate mass Charge

7. Complete the table below ProtonNeutronElectron LocationNucleusNucleus Electron cloud Approximate mass 1 amu 0 amu Charge+10

8. What is this and what was it used for?

9. Cathode ray tube  Used to discover the electron

10. What is meant by the term “electron cloud”?  A regional location outside the nucleus where the electron generally occupies.

11. Where do the masses on the periodic table come from?  It is the average of the various isotopes that that exist according to there relative abundances.  Ex.: O-16 is 99.757%  O-17 is 0.038%  O-18 is 0.205%

12. If something has: 47 protons 55 neutrons 46 electrons  What element is this?  What is the atomic number?  What is the charge?  What is the mass number?  Would it be called an atom or ion?

13. What does each symbol represent in this equation: c= What does each symbol represent in this equation: c=  c is the speed of light  is the wavelength  is the frequency

14. X-rays UV visible IR microwaves  Which has the largest frequency?  Which has the longest wavelength  Which travels the fastest?  Which has the most energy?

15. What is the photoelectric effect?  When light shines on a metal electrode, only light above a particular frequency could get electrons to move from the surface of the metal to an electrode.  This led to the understanding of frequency being related to energy.  E=hv where h is Planck’s constant

16. What is a photon?  A particle of light having zero mass and a quantum of energy

17. How is a line spectrum produced?

18.  Electrons begin in the ground state.  When they absorb energy, they move to an excited state.  When they return to the ground state, they give off certain wavelengths of light.  The wavelengths correspond to frequencies/energies from the excited states the electron fell from.

19. What were the shortcomings of the Bohr model of the atom?  It wrongly said electrons orbit the nucleus like planets orbit the sun  It only explained hydrogen’s emission spectra  It did not offer any explanation for the chemical properties of elements

20. How many electrons can be held in each sublevel?  s =  two  p =  six  d =  ten  f =  fourteen

21. What is the “octet rule”?  Atoms tend to gain, lose, or share electrons so that they get an octet (8) electron in their highest energy level.