Scientists estimate earth's age to be 4.6 billion years. samarium has a half-life of approximately 106 billion years. from the present date, approximately how many more years must pass before a sample of samarium that was created at the beginning of earth's history contains 50 percent of the original parent material? 1 billion 10 billion 100 billion 1,000 billion

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Read the following scenario to answer the following question. in some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." male ligers are sterile but some female ligers are fertile. in the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. applying the biological species concept, the sterility of ligers reveals that a. lions are probably a subspecies of tigers b. tigers and lions are the same species c. a new species called "ligers" is forming d. tigers and lions are separate species

Which statement about the pancreas is not true? a. it is an endocrine organ in the abdomen. b. it release chemicals into the digestive system. c. it releases insulin to increase glucose levels. d. it release hormones into the bloodstream.