Is the following salt an acid, base, or neutral? nh4clo4

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

The number of moles of a given mass of a substance can be found without knowing its molecular formula or molar mass. true false

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.