8. you and your friend, bill, are given a rock that you know has some silicon. you just learned that there are 3 common isotopes of silicon- silicon-28, silicon-29, and silicon-30. bill suggests that the rock might have equal parts of each isotope. what would be the average mass of silicon in the rock? show your calculations. how could you check to see if your ideas are correct?

Identify the missing numbers below to show the result of multiplying the numbers (1.6 × 10-19)(5.0 × 106) = c × 10d

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?

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.