Aluminum, Carbon, Cobalt, Copper, Zinc, Tantalum
Alchemist developed the tools and the techniques for working with chemicals.
Answer:
The retention factor, k is 2.49
Explanation:
According to the theory of High-Performance Liquid Chromatography (HPLC), the retention factor (or capacity), k, of a column is the ratio of the retention time of a retained analyte (toluene) to that of the un-retained solute (methane).
This implies that:
k =
= 
retention factor, k = 2.49.
Note that there is no unit for retention factor, as it is a ratio.