=Taro stated that when someone hits a golf ball with a club, the amount of energy the ball has changes, the amount of energy that the club has changes, and the total energy of the system that includes the ball and the club increases. Which best explains Taro’s error? The amount of energy that the ball has does not change.
The amount of energy that the club has does not change.
The total energy of the system remains the same.
The total energy of the system decreases.

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

Which common material is an example of a polymer? (25 pts) a. steel b. plastic c. petroleum d. rubbing alcohol

Ineed ! i have no clue how to do this problem.