Dmitri mendeleev's periodic law states that chemical and physical properties repeat themselves in groups of a. 4 b. 8 c. 12 d. 16

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?

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

Answer explain why it is not possible to deduce a complete order of reactivity.