An expandable balloon contains 0.857 mol of helium gas and has a volume of 1.65 L. A certain amount of argon gas is added to the balloon and it expands to 2.75 L. If there is no change in the temperature and pressure, what is the amount of argon gas that was added

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?

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

What happens to isotopes that are unstable?