4. As you have seen in this chapter, hydrogen is very different from the other elements ! Group 1.
a) Chemists have put hydrogen and he alkali metals in the same column of the periodic
table. Why?
b) Hydrogen is sometimes shown above Florine in the periodic table. Why?

Dumbledore decides to gives a surprise demonstration. he starts with a hydrate of na2co3 which has a mass of 4.31 g before heating. after he heats it he finds the mass of the anhydrous compound is found to be 3.22 g. he asks everyone in class to determine the integer x in the hydrate: na2co3·xh2o; you should do this also. round your answer to the nearest integ