Given the formula choose which answer provides the correct chemical name please use the periodic table that has been provided for use

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

the answer is barium and copper bromide