The table shows the results of four surveys that randomly sampled 50 girls at a community center about their favorite sport at the center. swimming basketball soccer total survey 1 16 15 19 50 survey 2 15 15 20 50 survey 3 7 35 8 50 survey 4 14 18 18 50 identify surveys that are likely biased. based on the unbiased surveys, what percent of the girls at the community center are likely to choose swimming as their favorite sport? 14 % 23 % 26 % 30 %

Asample contains 16.75 g of the radioisotope u-236 and 50.25 g of its daughter isotope, th-232. how long did it take for decay to take place if one half-life of u-236 is 23 million years? 46 million years 69 million years 92 million years 115 million years

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.