Use a proportion or dimensional analysis to determine the amount of energy (in kJ) needed to ionize 7.5 mol of sodium (Na(g) + 496 kJ →Na+(g) + e–).

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.