I used to know this. I don't really remember but is used to know it. Im in 6th grade now
<span>The electronic configuration of cobalt is :1s2 2s2 2p6 3s2 3p6 3d7 4s2 </span>
Answer is: B because it has a lower activation energy.
For all chemical reaction some energy is required and that energy is called activation energy (energy that needs to be absorbed for a chemical reaction to start), activation energy for reaction B is lower that for reaction A.
Catalysis is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalyst.
Chemical reactions occur faster with a catalyst because they require less activation energy.
The correct answer is B. The concentration of a solution does not decreases when you add more solute to the solvent. Instead, the concentration increases. Concentration is expressed as the amount of solute per unit of solvent. Therefore, increasing the solute, increases this value and increasing the solvent, decreases this value.