What is the density if the weight is 40.5 and the volume is 15.0

If 200.0g of copper(ll) sulfate react with an excess of zinc metal, what is the theoretical yield of copper

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

Which kind of weather usually forms over the northwest united states in the summer because of maritime polar air masses? 1 )fog 2)dry heat 3) heavy snow 4) heavy rain