Copper has two naturally occurring isotopes, 63cu (isotopic mass 62. 9296 amu) and 65cu (isotopic mass 64. 9278 amu). If copper has an atomic mass of 63. 546 amu, what is the percent abundance of each isotope? report your answer to 5 significant figures.

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.

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy

What are the two major rules associated with polarity