Atomic Structure and Electron Configurations Notes

Atomic Structure

  • Understanding Atomic Structure:

    • Atoms consist of protons, neutrons, and electrons.

    • Protons and neutrons are located in the nucleus, while electrons orbit the nucleus in energy levels.

  • Energy Levels and Sublevels:

    • Each energy level can have one or more sublevels, which determine the shape of the electron cloud.

    • 4th Energy Level Sublevels: 4s, 4p, 4d, 4f, 3d.

Key Questions & Concepts

Sublevels in the 4th Energy Level

  1. Name the sublevels that exist on the 4th energy level:

    • Answer: 4s, 4p, 4d, 4f

  2. Which sublevels fill across the 4th period of the periodic table?

    • Answer: 4s fills before 3d, followed by 4p.

Energy of Sublevels

  1. Which of the following sublevels has the greatest energy? (Choose from: 1s, 3s, 5s, 7s)

    • Answer: 7s has the greatest energy.

  2. Which of the following sublevels has the least energy? (Choose from: 4s, 3p, 3d, 4p)

    • Answer: 4s has the least energy among these options.

Ionization and Electron Configuration

  1. An electron in which sublevel would require the most energy to remove?

    • Typically, electrons in higher energy levels (higher principal quantum number) will generally require more energy to be removed.

Element Characteristics

  • Nitrogen (N):

    • Type: Nonmetal

    • Protons: 7

    • Electrons: 7

    • Unpaired Electrons: 3

    • To complete its octet, nitrogen must gain 3 electrons.

  • Silicon (Si):

    • Type: Metalloid

    • Protons: 14

    • Electrons: 14

    • Unpaired Electrons: 4

    • To complete its octet, silicon must gain or lose 4 electrons.

  • Magnesium (Mg):

    • Type: Metal

    • Protons: 12

    • Electrons: 12

    • Unpaired Electrons: 2

    • To complete its octet, magnesium must lose 2 electrons.

Electron Configurations
Full Electron Configurations for Atoms and Ions:

  • Iron (Fe):

    • Configuration: 1s22s22p63s23p64s23d101s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10}

    • Protons: 26, Electrons: 26

  • Iron Ion (Fe³⁺):

    • Configuration: 1s22s22p63s23p64s03d61s^2 2s^2 2p^6 3s^2 3p^6 4s^0 3d^6

    • Protons: 26, Electrons: 23

  • Chlorine (Cl):

    • Configuration: 1s22s22p63s23p51s^2 2s^2 2p^6 3s^2 3p^5

    • Protons: 17, Electrons: 17

  • Chlorine Ion (Cl⁻):

    • Configuration: 1s22s22p63s23p61s^2 2s^2 2p^6 3s^2 3p^6

    • Protons: 17, Electrons: 18

  • Barium (Ba):

    • Configuration: [Xe]6s2[Xe] 6s^2

    • Protons: 56, Electrons: 56

  • Barium Ion (Ba²⁺):

    • Configuration: [Xe]6s0[Xe] 6s^0

    • Protons: 56, Electrons: 54

  • Carbon (C):

    • Configuration: 1s22s22p21s^2 2s^2 2p^2

    • Protons: 6, Electrons: 6

  • Carbon Ion (C⁴⁺):

    • Configuration: 1s22s21s^2 2s^2

    • Protons: 6, Electrons: 2

  • Yttrium (Y):

    • Configuration: [Kr]5s24d1[Kr] 5s^2 4d^1

    • Protons: 39, Electrons: 39

  • Yttrium Ion (Y³⁺):

    • Configuration: [Kr]5s04d0[Kr] 5s^0 4d^0

    • Protons: 39, Electrons: 36

Summary of Charge and Electrons in Ions

  • To determine the number of electrons in an ion:

    • If an atom loses electrons (cation), it's positive charge is equal to the number of electrons lost.

    • If an atom gains electrons (anion), it's negative charge is equal to the number of electrons gained.