Which substance is a compound

salt
phosphorus
sulfur
oxygen

What happens when a magniseum ion ia atracked to a chlrene ion

Photosynthesis converts light energy to chemical energy. which molecules are the end product of this transformation of energy in this reaction?

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?