Please help i will mark brainlist

V= 21 cubic cm (( I am not sure about density ))

Explanation:

V= L×W×H

volume = 21 cubic cm or 21 cm^3

density = 3 g/cm^3

Explanation:

volume = length × breadth × height

hence, volume = 21 cubic cm.

density = mass / volume

i hope it helped. ...

let that person have a turn to speak : )

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.