PLEASE HELP MEEE this is due like in 10 min

how do you explain that 1 OF2 + H2o --> 1 O2 + 2 HF demonstrates that mass is conserved in a chemical l reaction

At room temperature what happens to the average kinetic energy of the molecules of a solid, liquid, and a gas

Name the element in group 17, period 2. (periodic table)

Plz mark brainliest 30 points1) 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?