Discuss how humans can fight and prevent disease. (Include 3 examples)

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

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.

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh