This document provides an introduction to chemical symbols and formulas for elements and compounds in science. It lists common chemical formulas such as Fe2(CO3)3 for iron carbonate and H2O for water that should be memorized. It then asks the reader to identify the elements that make up the compound NaCl, with the correct answer being sodium and chlorine. The document emphasizes that learning science symbols and formulas is an important part of developing fluency in using science as a language.