PDF chapter test TRY NOW

Fill in the blanks with a suitable answer.
  
(a). In a chemical reaction, the sum of the masses of the reactants and products remains unchanged. This is called __________.
 
(b). A group of atoms carrying a fixed charge on them is called __________ .
 
(c). The formula unit mass of \(Ca_3(PO_4)_2\) is __________.
 
(d). Name of \(Na_2CO_3\) is __________ and that of \((NH_4)_2SO_4\) is __________.