CHEM 1123 Unit 1 – Introduction, Matter, Elements, and Symbols

Chemistry: Quick Definitions

  • Chemistry is the study of the composition, structure, properties, and reactions of substances.
  • Chemicals appear in daily life: clean drinking water, plastics, baking soda, detergents, gasoline, processed foods, medicines.
  • Chemical reactions occur when energy or processing is involved (e.g., using a battery, digestion, burning) and produce new substances.
  • A chemical is anything used in or produced by a chemical process; a chemical = a substance.

Matter and Substances

  • Matter is the physical “stuff” that makes up all things.
  • Matter has mass and takes up space (volume).
  • All substances (chemicals) are forms of matter.

Pure Substances; Elements and Compounds

  • A pure substance contains only one kind of matter with a fixed composition.
  • Two kinds of pure substances: elements and compounds.
  • Elements: cannot be broken down by chemical reactions; contain atoms of only one type; listed on the periodic table.
  • Atom: the smallest unit of matter that can be identified as an element.
  • Compounds: another form of pure substance (not elaborated here).

Elements and the Periodic Table

  • Elements are listed on the Periodic Table of Elements.
  • Origin of a few element names: carbon (Latin carbo = coal); iodine (Greek iodes = violet); curium (named for Marie Curie).

Element Symbols

  • An element symbol represents the name of an element.
  • Single-letter symbols: C = carbon, N = nitrogen, F = fluorine (examples).
  • Two-letter symbols: first letter capitalized, second letter lowercase (e.g., Co = cobalt, Ca = calcium, Mg = magnesium).
  • Some symbols come from Latin names: Cu = copper (cuprum), Au = gold (aurum), Fe = iron (ferrum).

Memory Work: Element Names and Symbols

  • You are responsible for knowing the correctly spelled names and element symbols for the 21 elements shown in Unit 1 syllabus.
  • Correct spelling follows the syllabus; chemical names are not proper nouns and are not capitalized.
  • Examples: Ca = calcium, K = potassium, P = phosphorus, S = sulfur, Na = sodium, Al = aluminum.
  • Flash cards are a recommended study method.

Writing Element Symbols

  • Do not use cursive letters; print symbols.
  • In two-letter symbols, the first letter is uppercase and the second letter is lowercase.
  • Why? To distinguish elements from compounds (e.g., Co vs CO).
  • Example of a common pitfall: cobalt = Co, carbon monoxide = CO.
  • Take the time to make each symbol clearly and correctly.