Which of the following chemical reactions is balanced?

When will le chatelier's principle come into effect? at the beginning of a reaction, when there are only reactants when a reaction has reached chemical equilibrium when a catalyst is added to a reaction mixture when a reaction is occurring but not yet at equilibrium

How are isotopes of the same chemical element alike? how are they different?

Write and balance the chemical equation that represents the reaction of aqueous sulfuric acid with aqueous sodium hydroxide to form water and sodium sulfate. include phases.