Aflask with a volume of 12.0 l contains 4.25 mol of oxygen gas at 15ºc. how many moles of nitrogen gas must be added to give a total pressure of 10.0

How air particles exert a pressure on the inside of the balloon

If 15 drops of ethanol from a medical dropper weight 0.60g, how many drops does it takes from a dropper to dispense 1.0ml of ethanol? the density of ethanol is 0.80g/ml

Which property of a rock remains unchanged by mechanical weathering? a. total surface area b. size and shape c. mineral composition d. sharpness