Is scrap metal pieces an example of a pure substance or a mixture ?

Asingle atom of an element has 21 neutrons, 20 electrons, and 20 protons. which element is it? ok o z

Select the correct answer. given: 2libr + ba → babr2 + 2li in this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced? a. 1.18 mol b. 2.37 mol c. 4.73 mol d. 16.4 mol e. 32.9 mol

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?