A ballon is filled with helium and oxygen with a volume of 55.5 L of gas, how many moles is that?

Which best describes why nh4+ can form an ionic bond with cl-?

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.

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery