What are alpha particles

Harvey mixes two liquids. which observation of the new mixture most likely indicates a precipitate is forming?

Kc = 0.040 for the system below at 450oc. if a reaction is initiated with 0.40 mole of cl2 and 0.40 mole of pcl3 in a 2.0 liter container, what is the equilibrium concentration of cl2 in the same system? pcl5(g) ⇄ pcl3(g) + cl2(g)

What substance has a mass of 9.5g and volume of 2.1cm^3