The recommended daily allowance (RDA) of calcium is 1.0 g for men and women from 19-50 years of age. Calcium carbonate CaCO3 contains 12.0% calcium by mass. How many grams of calcium carbonate are needed to provide the RDA of calcium?

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots

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?

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.