1. Shape grows tired of these conceptual questions and thinks it’s time for a problem. What is the retention factor if the distance traveled by the solvent front is 2.00 cm, and the distance traveled by the ion is 0.40 cm?

2. Harry wants to know if there are any applications of chromatography. Gel elec-trophoresis is such an example. Gel electrophoresis is an example of which type of chromatogaphy?

(A) Column chromatography

(B) Gas chromatography

(C) Paper chromatography

(D) Thin-layer chromatography

3. Safety Review: Can you have food or drink in the lab.

(A) Yes, you can have food and drink in the lab. (this is not. the correct answer, don’t choose it

(B) No, you can never bring food or drink into the lab. Furthermore, all food waste, included empty water bottles must be disposed of before entering the lab. If the ministry of heath stops by they will look in the trash cans, searching for water bottles. If they find any: Prof. Vitarelli will be sent to Azkaban. He will be replaced by Professor Umbridge.

4. Review of Significant F igures: How many significant ?gures (1095 the result. of the following calculation have: 24.78*(37.3-31.72)?

(A) One significant figures

(B) Two significant figures

(C) Three significant figures

(D) Four significant figures

5. Lastly, Snape thinks we should try one more calculation. What is the retention factor if the distance traveled by the solvent front is 2.0 cm, and the distance the ion is from the solvent front is 0.20 cm?