I got the answer but I'm quite lost as to how my teacher got the answer. Please help. A substance is found to consist of 1.90 g of sulfur, and 2.09 g of oxygen. What is the percent by mass of oxygen in this compound?
52.4%

The following transition occurs at a molecular level for a substance. what transition corresponds to this change in microscopic structure? the carbon dioxide molecules on the left are in a regular, tightly packed pattern. after heating, it becomes much lower density. a. melting b. boiling c. sublimation d. freezing