The precipitate from Question 1 that possibly contains Ca, Mn, Fe, or Co, is washed twice, first with a 1 mL portion of 1 M NaOH and then with 1 mL of deionized water. The tube is centrifuged after each washing and the two supernatant liquids are discarded. Now the precipitate is treated with 1 mL of 6 M HNO3 and the test tube is heated briefly in a water bath. The test tube is then centrifuged, and the supernatant liquid is decanted and saved. (The Ca(OH)2 produced in Question 1 is acid soluble.) At this stage of the experiment, which elements could be found in the DECANTED LIQUID