I just need these help with these 2 the second one seems answered but I accidentally clicked it, it’s not answered

Several kinds of bears are found on earth. most bears are brown or black, but one type of bear, the polar bear, is white. what process led to this difference in fur color? explain your answer.

Write the balanced equation for a reaction between aqueous nitric acid (hno3) and solid lithium metal (this is a single replacement reaction)

Compare and contrast physical changes with chemical changes.