What is the smallest particle of an element that still has the same chemical properties?

Reaction rate depends on how many molecules are coming into contact with each other with enough energy to react. increasing the temperature of the reactants will increase -

What is the mass of 4 molecules of co2

When hydrochloric acid reacts with potassium hydroxide solution, the following reaction occurs. hcl (aq) + koh (aq) h2o (l) + kcl (aq) the reaction gives off heat energy, so it is an reaction.