What overall effect does adding a catalyst have on a chemical reaction?

The overall effect of a catalyst to the reaction is that it lowers the activation energy of a chemical reaction. Catalyst is a substance that speeds a chemical reaction. It is not consumed as the reaction proceeds. A catalyst offers a new route for faster reaction. 

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.