Giselle is pairing ions to create stable binary ionic compounds. she knows that the sum of charges of the two ions must be zero in order for the compound to be stable. which ion could be paired with a potassium ion, k +, to form a stable binary compound?

In a game of pool, ball a is moving with a velocity v0 of magnitude v0 = 15 ft/s when it strikes balls b and c, which are at rest and aligned as shown. knowing that after the collision the three balls move in the directions indicated and assuming frictionless surfaces and perfectly elastic impact (that is, conservation of energy), determine the magnitudes of the velocities va, vb, and vc.