Question 20(Multiple Choice Worth 2 points)
A scientist measures the rate of a reaction between two liquids. Then, he performs the reaction again, adding solid manganese. The reaction takes place more quickly the second time. The mass of the manganese decreased by 0.45 grams during the reaction. He claims that the manganese acted as a catalyst because it sped up the reaction. Is the scientist correct? Why or why not?

Yes, because the reaction happened more quickly with the manganese.
Yes, because the manganese was a solid, and all solids are catalysts.
No, because manganese is a metal, and metals cannot be catalysts.
No, because some manganese was used during the reaction, and catalysts are not used up.