From their location on the periodic table, identify the oxidation state and number of valence electrons for calcium and chlorine. Then use this information to describe their reactivity.

Location in the periodic table:

Calcium is in group II Alkali Earth Metal

Chlorine is in group VII Halogens

Oxidation State:

Calcium is 2+ a cation

Chlorine is -1 an anion

Valence electrons:

Calcium has 2 valence electrons

Chlorine has 7 valence electrons

Explanation: Based on the information above it implies that Calcium is more reactive than Chlorine. In most cases Ca is more reactive when it comes to Halogens. Chlorine is near to octet on its outer orbital so it is hard for it to remove an electron. This cause it to become less reactive than Calcium.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"