Sodium-24 has a half-life of 15 hours. How much of a 20 mg sample would remain after two half-lives? 5 mg
2 mg
omg
10 mg

In which reaction is precipitation occurring?

Select all that apply. using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 (s) pb+2(aq) + 2cl -(aq). the concentration of the products yield a ksp of 2.1 x 10-2:

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.