conversions

1. Unit Conversions

  • Length:

    • Convert 2.5 kilometers to meters:
      2.5extkm×1000 m/km=2500 m2.5 ext{ km} \times 1000 \text{ m/km} = 2500 \text{ m}

  • Mass:

    • Convert 500 milligrams to grams:
      500extmg÷1000 mg/g=0.5 g500 ext{ mg} \div 1000 \text{ mg/g} = 0.5 \text{ g}

  • Volume:

    • Convert 3.0 liters to milliliters:
      3.0extL×1000 mL/L=3000 mL3.0 ext{ L} \times 1000 \text{ mL/L} = 3000 \text{ mL}

2. Significant Figures

  • Example 1: The measurement 0.00456 has three significant figures (4, 5, and 6).

  • Example 2: The number 1002 has four significant figures.

  • Example 3: In the measurement 0.03040, there are four significant figures (3, 0, 4, and the trailing 0).

3. Quantum Numbers

  • An electron in an atom can be described by four quantum numbers:

  • Principal Quantum Number (n): Indicates the energy level (e.g., n = 2).

  • Angular Momentum Quantum Number (l): Determines the shape of the orbital (e.g., l = 1 for p-orbital).

  • Magnetic Quantum Number (ml): Specifies the orientation of the orbital (e.g., ml = -1, 0, +1 for p-orbitals).

  • Spin Quantum Number (ms): Represents the spin direction of the electron (e.g., ms = +1/2 or -1/2).