What do the presence of fish and a wide diversity of invertebrates in a river indicate regarding water quality?

Astudent is asked to identify and element that is pale yellow brittle solid and does not conduct electricity. at which location in this periodic table would the element most likely be found?

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

What was bohr’s contribution to the planetary model