What residue is left behind when lake water is heated?

When lake water is heated, the residue left behind primarily consists of dissolved minerals and organic matter that were present in the water. Common minerals include calcium, magnesium, and sodium salts, which can precipitate out as the water evaporates. Additionally, any particulate matter, such as sediments and organic debris, may also remain. The specific composition of the residue can vary depending on the lake's chemistry and the surrounding environment.