Overview
This lecture covers the importance of scientific notation in chemistry, how to convert numbers to and from scientific notation, and its usefulness in handling very large or small values.
Why Use Scientific Notation?
- Scientific notation simplifies working with extremely large or small numbers commonly found in chemistry.
- It helps reduce errors by clarifying the number of significant figures in a value.
- Scientific notation makes calculations like multiplication and division easier.
Converting to Scientific Notation
- Move the decimal point in the number until only one nonzero digit remains to its left.
- Count the number of places the decimal moves; this is the exponent on 10.
- If you move the decimal to the left, the exponent is positive; to the right, it's negative.
- Example: 10000 becomes 1 × 10⁴ in scientific notation.
Converting from Scientific Notation to Standard Form
- To convert 1 × 10⁴ to standard form, move the decimal right 4 places: 10,000.
- For negative exponents, move the decimal left; e.g., 2.5 × 10⁻³ is 0.0025.
Math Concepts Needed for Chem 121
- Be able to convert numbers back and forth between standard and scientific notation.
- Understand how to multiply and divide numbers in scientific notation.
Key Terms & Definitions
- Scientific Notation — a method of expressing numbers as a product of a coefficient and a power of ten (e.g., 2.3 × 10³).
- Exponent — the number indicating how many times 10 is multiplied (positive for large numbers, negative for small numbers).
- Significant Figures — digits in a measurement that are known with certainty plus one estimated digit.
Action Items / Next Steps
- Practice converting numbers between standard and scientific notation.
- Review how to multiply and divide using scientific notation for chemistry calculations.