Rubidium-87 has a half-life of 48.1 billion years. after how many years is there 25 percent parent isotope and 75 percent daughter isotope contained in the object?

Arrange these elements of the intrinsic conduction system in the order that a depolarizing impulse travels during a normal heartbeat. rank from first to last. do not overlap any tiles. view available hint(s) reset av nodeav bundleinternodal pathwaysbundle branchessa nodepurkinje fibers

Cassandra made a venn diagram to compare and contrast the two stages of cellular respiration. which belongs in the area marked x? energy is released. oxygen is used up. glucose is broken down. carbon dioxide is used up.

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because