Gold is one of the densest substances known, with a density of 19. 3 g/cm^3. If the gold in the crown was mixed with a less-valuable metal like bronze or copper. How would that affect its density?

if gold has a rare, high density then it would sink quickly. If mixed substances that are less-valued, are added to the gold crown (remember that gold is rare and very dense which makes it special) then we can assume the cheap substances are less dense, thus making the crown FLOAT more rather than sink (I say more, because unless the crown was extremely mixed with cheap material then it could possibly float but it depends on how much is in the crown). Summary: The crown would either be lighter and float, or barely be sunken due to the less-dense substance.

*Hint to think about: People consider cheaper things lighter such as plastic ring/less dense  for example, compared to a silver ring which is heavier/more dense (btw heavy does not always mean high density, it depends on the liquid density )

Explanation:

- decrease the number of plants and animals living in the water.