Identify the four parts of the potential energy diagram. products
reactants
activation
energy
energy released
by reaction

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.

i think its 5049.

i hope this !

the answer is barium and copper bromide