An atom of helium is smaller in width then an atom of hydrogen, but it's more then twice the mass. Why are these different?

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %

Plz mark brainliest 30 points 1) find the momentum of a 12 kg snowball that is rolling with a velocity of 9 m/s. 2) an 8 ball with a mass of .5 kg is sitting at rest. it is hit by the cue ball (1 kg) traveling at 2.5 m/s. if the cue ball is at rest after the collision, how fast is the 8 ball traveling after the collision? 3) two football players are running toward each other. if the offensive player is 75 kg and is running 8 m/s, how fast must the 60 kg defensive player run in order for the two players to hit and stop?

What is the independent variable in this investigation? mass volume sample number substance density