Which of the following best decribes the fluoride content of bottled water? unpredictable, high, low, moderate

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

Ablock of aluminum is dropped into a graduated cylinder with an initial volume of water at 75ml and the volumes rises to 90ml. if the block has a mass of 40.5 g what is its density ?

Moving force of air flows from areas of high pressure to areas of low pressure true or false