In an atom, electrons a. are located in the nucleus c. travel outside the nucleus b. are paired with neutrons d. are always in the same place in an atom

They travel outside the Nucleus in three different energy levels hope this helps

They did not study the continental drift

In reversible reaction chemistry equilibrium is attained when the forward and reverse reactions are taking place at the same rate, thus, the concentrations of reactants and products remain the same. a reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back. in irreversible reactions on the other hand, the reactants react to form the products, which cannot revert back into reactants.