In two or more complete sentences explain how to balance the chemical equation and classify its reaction type. ___Al2(CO3)3 ⟶ ___Al2O3 + ___CO2

Al₂(CO₃)₃ → Al₂O₃ + 3CO₂     Decomposition

Explanation:

This reaction is a decomposition type, we make two compounds from one. This is the case where a single substance breaks down, producing two or more different substances. In orden to balance it we need to count.

We have 2 Al in both sides so at least it is balanced, but we have 3 C in reactant side from the carbonate and we may need 3 C in product side.

In conclussion we have 2 Al and 3 C on both sides. In reactant side we count 9 O so in product side we have 6 O from the Co₂ and 3 O from the aluminum oxide. Finally the reaction is balanced

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.