What is the minimum amount of heat required to completely melt 20.0 grams of ice at its melting point?
(1) 20.0 j (3) 6680 j
(2) 83.6 j (4) 45 200 j

For each of the compounds below, show that the charges on the ions add up to zero. a. kbr b. cao c. li(2)o d. cacl(2) e. alcl(3)

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.