Why is formula of calcium bromide CaBr2?

Answer 1

as you know, in writting a formula the valencies interchanges, if you remember the valency of calcium is 2, because it is the 20th element, and the valency of bromine is 3,so that atom of bromine we know is 3,but remember that bromine is a transition metal in five blocks of metals, this means that it can adopt the characteristics of its peer reactant,so in general anyway bromine react with calcium its valency tends to be 1(in other ways it is not must to be written), which after it reacts witso that is why you can see as it is! Bromine with 2 valencies and calcium with only one.

i hope i tried to answer, thanks.

Answer 2

Calcium bromide has the formula CaBr2 because calcium (Ca) is a group 2 element with a +2 charge, and bromine (Br) is a group 17 element with a -1 charge. In order to form a neutral compound, two bromine ions (each with a -1 charge) are needed for every calcium ion (with a +2 charge), resulting in the formula CaBr2.