How can you tell whether a substance is ionic or covalent?

For the following reaction, 5.65 grams of oxygen gas are mixed with excess hydrochloric acid . assume that the percent yield of water is 86.4 %. hydrochloric acid(aq) + oxygen(g) water(l) + chlorine(g) what is the ideal yield of water ? grams what is the actual yield of water ? grams

What is the chemical formula of the following compound

Complete the table for ion charge based upon their losing or gaining electrons in the outer shell. (use the periodic table as necessary.) group most likely ionic charge # of valence electrons i +1 ii +2 iii +3 iv +4 or -4 v -3 vi -2 vii -1 viii 0