Which is the most dense substance in the list a. aluminium b. lead c. oxygen d. water

Asap! how do you lengthen a pattern piece? (family and consumer science, sewing)

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

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.