1. What do chemists
collect?
2. What did
chemists develop in order to classify and organize elements?
3. According to
figure 5-2, when were the majority of chemicals discovered?
4. At the end of
the 1700’s how many elements had been discovered?
5. What “new”
technique did scientists use to discover additional elements?
6. How did this
technique identify new elements?
7. In the early
1800’s what scientists classified elements into threes?
8. What did he call
these sets?
9. What did these
sets have in common?
10. What law did
Newlands discover?
11. How did
Newlands arrange the elements?
12. Who received
the credit for discovering the periodic table?
13. Who also
created a periodic table at the same time as Mendelev?
14. Why did
Mendelev switch the order of three pairs of elements?
15. Instead of
ekasilicon what name was given to that element discovered?
16. Why were some
of the elements still out of order on Mendelev’s table?
17. Who discovered
the concept of atomic number?
18. Who did this
scientist work for?
19. When do metals
produce X-rays?
20. Did these
X-rays differ?
21. How did they
differ?
22. What is the
correct to organize the elements?
23. Was Mendelev’s
periodic table valid?
________________________________________________________________________
Answer these questions completely:
1) What is the
periodic law?
2) How did
Dobereiner help to develop the periodic table?
3) What did Mosely
contribute to the development of the periodic table?