Magnesium combines with oxygen to form magnesium oxide. If 10.57 g of magnesium reacts completely with oxygen to form a compound with a mass of 17.53 g, then: a. The mass of oxygen in the compound is: b. The percent of magnesium in magnesium oxide is: c. The percent of oxygen in magnesium oxide is:

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.