oxygen is the answer
B. 3 protons, 1 electron, and 3 neutrons.
C. 2 protons, 2 electrons, and 1 neutron.
D. 3 protons, 2 electrons, and 1 neutron.
(1) A catalyst is added as an additional reactant
and is consumed but not regenerated.
(2) A catalyst limits the amount of reactants used.
(3) A catalyst changes the kinds of products produced.
(4) A catalyst provides an alternate reaction pathway
that requires less activation energy.