 We're going to do a flame test on a number of selected compounds, primarily group 1 and 2 ions. And these are aqueous solutions and we have just a inert metal loop. We're going to dip the end into the solution and put it into the flame. And that excitation characteristic color is like a fingerprint for an element. So we're going to look at a number and then we're going to ask you to identify some unknowns. Potassium. It should be a lavender. This is barium. It's a green. This is calcium. Sort of a yellow-red. Strontium. This one's a pretty red one. Lithium. Sodium is a bright yellow. And the last one is copper. This is the most vivid of all of them. Nice green.