Which of these compounds is most likely to be ionic? select one: a. ncl3 b. bacl2 c. co d. so2 e. sf4?

The compound that is most likely to be ionic is BaCl2
Ionic compounds are compounds made up of ions. These ions are atoms that gain or lose electrons, giving them a net positive or negative charge. Metals tend to lose electrons, thus they become cations and have a net positive charge. Non metals tend to gain electrons, forming anions that have a net negative charge. 

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2