The catalyst (4) decreases the activation energy required for a reaction, by holding reactants in place
Answer: An oxygen atom in heavy water has an extra neutron. A hydrogen atom in heavy water has an extra proton.
Explanation:
Gold has a very high density of about 19.32g/cm^3 while Aluminum has a low density of 2.7 gm/cm^3 which means gold can pack more amount of matter in a comparatively small space as compared to Aluminum.
