Predict which of the following metals reacts with hydrochloric acid. Check all that apply.
-Sn
-Hg
-Cr
-Ni

Which compound contain an iron with a 3+ charge

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?

Analyze the reaction to determine whether the reaction is exothermic or endothermic. explain your reasoning.