day 2 week 4

13. a.  a horizontal row
     b. a column is a group or family of elements


14. Sodium, Na
      Potassium, K


15. a. the noble gases are located on the far right side of the periodic table
     b. the noble gases are all odorless
     c. the noble gases are all unreactive


16. a. MgF2
     b. GaP


17. 68.5 degrees C is the melting point of potassium.


18. The boiling point of chlorine is higher than the boiling point of iodine.


19. a. carbon
     b. carbon
     c. 20
     d. 20
     e. Pt
     f. 78
     g. 92
     h. 92


20. On paper


21. A lead atom must have lost two electrons to make the ion.


22. a. C-12
         C-13
         Ca-41
         Pt-195
         U-238


     b. Carbon has two isotopes
   
23. The information is not sufficient because you do not know the number of protons.


24. The mass of an electron is way smaller than the masses of a proton and neutron.


25. a. 12
      b. 12
      c. 12
      d. 13
      e. 12
      f. 14