Are pure substances made up by only one kind of

4. how does a phospholipid behave in water? the phosphate head does not mix with water; the fatty acid tails do. the phosphate head and the fatty acid tails mix with water. the phosphate head and the fatty acid tails do not mix with water. the phosphate head mixes with water; the fatty acid tails do not.

The theories on the expansion of galaxies maybe re-examined to strengthen science should not be tested to strengthen science will weaken scientific knowledge if they change will become laws if they don't change

Select all the correct answers. which statements fail to meet the requirements of a scientific claim? a) in the final 100 meters of a 10,000-meter race, an athlete's speed is more strongly related to anaerobic efficiency than to aerobic efficiency. b) flowers that reflect the most ultraviolet light are more likely to attract bees and other pollinators than flowers that reflect less ultraviolet light. c) even though evidence indicates that the solar system's planets follow elliptical paths, copernicus's model involving circular orbits is true. d) the evidence supporting newton's laws of motion was accurate in newton's time, but the universe operates differently today.