A student dissolved 0.515 mol of magnesium chloride in enough water to make 225 mL of solution. What is the molar concentration of the magnesium ion in solution?

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

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?

In 2002, the rare earth elements mine in mountain pass, california was closed because