Complete this problem: Caffeine, which occurs in coffee, tea, and kola nuts, is a stimulant for the central nervous system. A 1.262g sample of pure caffeine contains 0.624g C, 0.065g H, 0.364g N, and 0.208g O. What is the empirical formula of caffeine?

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

Word equation for k(s)+h2o(l) yield koh(aq) + h2(g)

What is the chemical name of the compound na2co3? use the list of polyatomic ions and the periodic table to you answer. a. sodium carbon oxide b. sodium carbonate c. sodium(ll) carbonate d. sodium oxalate