The lifting force of a helium balloon is equal to the difference in mass between a balloon full of air and a balloon full of less dense gas. calculate the volume and radius of a balloon needed if it is desired to have a lifting force (mass) of 1000 kg when the temperature is 290 k at 0.940 atm. the balloon is to be filled with helium. assume that air is 80 mol % n, and 20 mol % o2

The diagram below shows a cell placed in a solution. a cell is shown placed inside a beaker. it is labeled cell. the solution inside the beaker is labeled 40% salt solution and the solution inside the cell is labeled 20% salt solution. only water is allowed to move in and out of the cell. what will most likely happen to the cell? it will expand as water moves out of it. it will shrink as water moves out of it. it will expand as water moves into it. it will shrink as water moves into it.

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

What is the indicator of the number of ions in solution? the amount of conductivity the amount of precipitate the amount of solute added