Standard Chemistry - Atomic History and Structure test
1. Who was the first person to suggest that atoms existed and during what era of history did he live?
2. Dalton also said that there are atoms. How did he describe them?
3. What did Crookes do? (Draw a picture of the apparatus he built. Tell what he saw and what he figured out.)
4. J.J. Thomson figured out that Crookes tube was filled with electrons. What else did Thomson do?
5. a)Rutherford discovered the nucleus. Draw the experiment he used. Label all important parts.
b)What did Rutherford expect to see?
c)What did he really see?
d)Rutherford figured that the nucleus was small and heavy. Why did he think it was small? Why did he think it was heavy?
6. a) How many protons, neutrons and electrons do the following have?
136C-4 14355Cs+1 14058Ce+2
b) While walking down the street, you stumble over an ion with a mass number of 289, 146 neutrons and a charge of –4. How many electrons, protons and neutrons does it have?
7. a)Draw the experiment done by Millikan. Label all the parts.
b)When Millikan got the drop to hang in mid-air he said that mg=Eq. What do each of those letters stand for?
c)How did Millikan find the mass of the drop?
d)Imagine that Millikan found the following numbers for the charges on 7 drops of oil. What would the charge of one electron be?
22.2, 7.4, 14.8, 11.1, 25.9, 18.5, 0
e)Once Millikan had found the charge on a single electron he wasn’t quite done. What did he do then and what information did he need in order to do it?