Living By Chemistry SECOND EDITION Unit 1: ALCHEMY Matter, Atomic Structure, and Bonding

Lesson 6: A New Language Chemical Names and Symbols

ChemCatalyst Two bottles are on a shelf in a chemistry lab. Both contain a shiny yellow metal. Bottle A is labeled Au(s). Bottle B is labeled FeS2(s). What do you think the symbols on the bottles mean? Do you think both bottles contain gold? Why or why not?

Key Question What do chemical names and symbols tell you about matter?

You will be able to: define the terms element, compound, and aqueous recognize whether a substance is an element or a compound based on its chemical formula or symbol decipher some basic chemical formulas and symbols

Prepare for the Activity Work in groups of eight.

Discussion Notes The Language of Chemistry Symbol for sulfur Symbol for oxygen Symbol for copper Subscript for oxygen

Discussion Notes (cont.) All matter in the universe either is an element or is made of some combination of elements. Element: A unique substance that cannot be broken down into simpler substances through chemical processes. Elements serve as the building materials of all matter. Compound: A pure substance that is a chemical combination of two or more elements in a fixed ratio.

Discussion Notes (cont.) The first letter of an element’s symbol is always uppercase, and if there is a second letter it is always lowercase. Compounds are represented by chemical formulas. Chemical formula: A combination of symbols and subscripts that indicates the number and types of elements in a compound.

Discussion Notes (cont.) Some common groupings of elements have their own specific names. Substances come in different physical forms, called phases. Phase: The physical form a substance is in, such as solid, liquid, or gas. Phase is greatly influenced by temperature. Aqueous: A substance is aqueous when it is dissolved in water.

Wrap Up What do chemical names and symbols tell you about matter? Chemical symbols represent the elements. Each element has either a one- or two-letter symbol. The first letter is always uppercase; the second letter is always lowercase. The chemical formula of a substance indicates what elements are in it as well as the relative amounts of each element in that substance. The symbols (s), (l), (g), and (aq) indicate the physical form or phase of a substance and whether it is dissolved in water.

Check-In Imagine that you find a vial labeled Na2SO4(aq). What does the label tell you about what is in this vial?