Evidence of a chemical change would be A) melting
B) spinning top
C) spilled bucket of water
D)rusting car fender

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2

Scientists discovered fossils in several layers of the earth you see here. they found fossils of algae, snails, and clams in layer d. given that information, where do you think they found fossil evidence of simple land plants and amphibians?

Based on the formulas, select the compounds below that are covalent: kbr sif4 al2o3 co2 naco3 s7o2 pcl3 fe3n2 h2o s2f10