What two conversion factors would you need to use to find the number of hydrogen atoms in 2. 12 moles of propane (c3h8)?.

Afish fossil is found in a rock. a foot bone and tooth are found in an older layer of the same rock. what can scientists learn from the rock? a) the area changed from land to water. b) the area changed from water to land. c) the area has always been land. d) the area was once an ocean.