Notes on Subatomic Particles and Atomic Structure

Subatomic Particles

  • Definition: Subatomic particles are the particles that compose atoms; the term "sub" means "under".

  • Three Main Types of Subatomic Particles:

    • Proton

    • Charge: Positive (+)

    • Symbol: p⁺

    • Mass: Approximately 1 amu (atomic mass unit)

    • Function: Defines the identity of an element (atomic number).

    • Neutron

    • Charge: Neutral (0)

    • Symbol: n⁰

    • Mass: Approximately 1 amu; contributes to the atomic mass but does not affect the charge.

    • Function: Provides stability to the nucleus.

    • Electron

    • Charge: Negative (-)

    • Symbol: e⁻

    • Mass: Approximately 0 amu (considered massless for practical purposes).

    • Function: Involved in chemical bonding and reactions.

Location of Subatomic Particles
  • Modern Atomic Theory: Electrons exist in a cloud around a dense nucleus (composed of protons and neutrons).
  • Bohr Model Representation: Depicts the atom similarly to a solar system, where:
    • Nucleus: Contains protons and neutrons densely packed.
    • Electron Cloud: Electrons orbit around the nucleus; despite being very small, they still possess a tiny mass.
Key Characteristics of Atoms
  • Equal Number of Protons and Electrons: Atoms are neutral overall because they have an equal number of protons (+) and electrons (-).
  • Example Atom - Lithium:
    • Contains 3 protons and typically 4 neutrons.
    • Should have 3 electrons to maintain charge neutrality.
Understanding the Periodic Table
  • Element Identification:
    • Atomic Number: Represents the number of protons in an atom.
    • Chemical Symbol: A one or two-letter abbreviation for an element (e.g., H for hydrogen).
    • First letter is capitalized; second letter (if present) is lowercase.
    • Element Name: Derived from various sources, including chemical properties and mythology.
    • Atomic Mass: Total mass of protons and neutrons in the nucleus, represented as:
    • extMass=extProtons+extNeutronsext{Mass} = ext{Protons} + ext{Neutrons}
Color Coding Activity (Boron Atom)
  • Color Coding for Boron:
    • Protons: 5 (color to represent)
    • Neutrons: 6 (color to represent)
    • Electrons: 5 (color to represent)
    • Create a key that correlates colors with particles, and illustrate the Bohr model of Boron accordingly.