Question

the formula for barium bromide is BaBr2 not BaBr, similarly potasium iodide is KI not KI2and in many similar cases. pls tell me how to know this. that is how to write the formula for compound substances

Answer 1

for writing the formula for an y of the compund you need to write the name of the elements side by side then write their valency at the top of the elements then interchange their valency