Which type of chemical reaction does this word equation exemplify: calcium oxide combines with silicon dioxide to form a single product, calcium silicate?

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg