2. No.

5. Light waves are too long compared to the size of an atom to give a clear picture. The wavelengths of electron beams are small enough to give a resolve the shape of an atom.

9. More massive particles would be deflected less. Particles with higher charges would deflect more.

10. As positively charged alpha particles were shot towards an atom, something repelled them. Since electrons have a negative charge they would attract the particles, he concluded there must be some positive charge(s) present to repel the particles located in the nucleus.

15. Atomic mass would be about 99 amu (see periodic table), which is technetium.

16. 26 electrons.

19. The one electron can be boosted to many different energy levels. The transition back to its original state can then take many different "paths", each giving relating to a different wavelength.

20. 6 distinct transitions are possible. The fourth to the first giving the highest energy while fourth to third gives lowest energy.

21. Energies are the same.

23. The wave model tells us that the circumference of each orbit must be a whole number of electron wavelengths. Since the orbits are discrete (whole numbers) so are the energy levels associated with them.

2. There are 10^22 breaths of air ( total number of molecules/ number of molecules per breath) in the world's atmosphere. This is the same as the number of molecules per breath. For any breath evenly mixed throughout the atmosphere, we would average one of those molecules per breath.