Help pleas How can you determine an
ion's charge from its group
position on the periodic
table?

How many molecules are in 6.0 moles of methane

What is the compound name for the formula [ru(en)2cl2]2+ and [co(en)cl2br]-

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.