which of the bonds in calcium hydroxide, Ca9OH02, are ionic and which are covalent? i understand this at all, plz help me lol

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.

Reaction rate depends on how many molecules are coming into contact with each other with enough energy to react. increasing the temperature of the reactants will increase -

What are the 4 phases of matter in order of increasing engery content?