How many naturally ocouring elements are found on the earth in significant quantities?

How has urbanization impacted species diversity? How is isotope eliminated from the body? What is meant by cell specialization? What are the four elements most common in organisms? How does acne effect the integumentary system? Does salt solution show slow tyndall effect? Why is chromatography useful to a forensic expert? How does sound occur? Who is the strongest on the game dead or alive? What is noun of keen? What is the function of a spark in a reaction between oxygen and hydrogen gas? What did rogier verbeek do in relation to Krakatoa? What made up all radioactive elements? Why is the Dark Reaction sometimes called Light Independent Reaction? How can geologists determine how a rock was formed? What are some examples of basic solutions that are drinkable? What are the levels of organization in ecosystem? What are the function of the fibrils in an animal cell? What is Acoustic velocity? Why do astronomers theorize that quasars are active nuclei?