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?

The answer is a) carbon-12

4- c, because all matter stays the same no matter what. it is still there. 5- b, because matter is known as mass. 6-c because, flammability is a chemical property. malleability is changing the shape of an object.

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

The phase where ice changes directly to gas is called sublimation