Atomic Structure, Periodicity, and the Octet Rule

Periodicity and Electron Shell Configuration

  • An element's position on the periodic table provides direct information regarding its atomic structure.
  • The period number an elephant is located in indicates the total number of electron shells or orbitals it possesses:
    • Elements in the first period have 11 orbital.
    • Elements in the second period possess 22 shells.
    • Elements in the third period possess 33 shells.

Radioisotopes and Clinical Applications

  • Radioisotopes are defined as isotopes that undergo decay, a process that releases energy.
  • These isotopes can release various types of radiation.
  • In clinical settings, certain solutions containing radioisotopes or similar markers are used for diagnostic imaging:
    • A common procedure is a swallowing study, used to investigate issues such as a stricture eight in the anatomy.
    • The patient swallows a thick, chalky solution similar to crushed-up tablets mixed into a liquid.
    • A live X-ray is performed while the patient swallows, allowing medical professionals to see the anatomy functioning in real-time.
    • During the procedure, the "white area" of the solution can be observed as it travels down the esophagus on the screen.

The Octet Rule and Electron Capacity

  • Atoms have specific capacities for electrons within their various shells.
  • Electron shell distribution limits are as follows:
    • The first shell can hold a maximum of 22 electrons.
    • The second shell can hold a maximum of 88 electrons.
    • The third shell can hold a maximum of 88 electrons.
  • The Octet Rule is the principle that atoms are constantly attempting to fill their valence (outermost) shell to achieve stability.
  • Atoms can satisfy the octet rule through two primary methods:
    • Gaining electrons from other atoms.
    • Losing electrons to other atoms.

Atomic Analysis of Sodium

  • Sodium serves as a primary example for understanding shell configuration and the pursuit of the octet rule.
  • Sodium has 33 electron shells.
  • Because it has 33 shells, it is located in the third period of the periodic table.
  • Any element with 33 shells, such as the one labeled "40", would also be categorized in the third period.

Questions & Discussion

  • Question: Anybody know the different types of radiation radioisotopes can release?

    • Response: It's safe. I don't have to take it. It's safe, I hope.

  • Question: How many electrons can the second and third shell of an atom hold each?

    • Response: Eight. Eight.

  • Question: How many can the first shell hold?

    • Response: Two.

  • Question: How many shells does sodium have?

    • Response: Three.

  • Question: What does shell count mean about what period it is in? What period would you find it on the periodic table?

    • Response: Third period. Third period, three shells.

  • Question: How many valence electrons does sodium have?

    • Response: Positive. Positive two. It's called yep.

  • Question: How do you know that it would have lost two?

    • Response: Taken it and lost two.