What are the four ways to tell if a chemical change has occurred?

100mg magnesium reacts with 20ml of 1.0m hcl

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

Which atom or ion is the largest? 0 a. 0 0 0 0 e. li