Ionic bonding would most likely occur between which two elements?

Which formula can be used to calculate the molar mass of ammonia (nh3)? molar mass of n + molar mass of h 3 × molar mass of n + molar mass of h molar mass of n + 3 × molar mass of h 3 × molar mass of n + 3 × molar mass of h

Can someone me with 1 to 4 plz. fast

What is the polyatamic ion of thiosulfate