Pedro adds 1.25 moles of helium to a balloon that already contained 4.51 moles of helium creating a balloon with a volume of 8.97 liters. What was the volume of the balloon before the addition of the extra gas?

10.063g / 10.00 ml = 1.0063 g/ml which rounds off to 4 sig figs as: 1.006 g/ml

Yes you are correct use the scientific method

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy