Ytterbium (Yb): Atomic Structure & Chemical Properties

Atomic Model

Protons, Neutrons, Electrons

• Atomic Number (Z): 70
• Number of Protons: 70
• Number of Electrons: 70 (in a neutral atom)
• Number of Neutrons: Varies by isotope. For the most abundant isotope, Ytterbium-174 (¹⁷⁴Yb), the number of neutrons is 174 - 70 = 104.

Atomic Size

• Metallic Radius: Approximately 194 pm.
• Ionic Radius (Yb³⁺): Approximately 100 pm.

Electronic Configuration & Shell Diagram

Electronic Configuration

• Ground State Electronic Configuration: [Xe] 4f¹⁴ 6s²
  • This configuration indicates that the 4f subshell is completely filled with 14 electrons, and the outermost 6s subshell contains 2 electrons. These two 6s electrons are typically involved in chemical bonding.

Shell Diagram Representation (Textual Explanation)

The distribution of electrons in different electron shells (principal energy levels) for Ytterbium (Z=70) is as follows:

• K-shell (n=1): 2 electrons
• L-shell (n=2): 8 electrons
• M-shell (n=3): 18 electrons
• N-shell (n=4): 32 electrons
• O-shell (n=5): 8 electrons
• P-shell (n=6): 2 electrons

Periodic Trends

Ionization Enthalpy

• First Ionization Enthalpy (IE₁): Approximately 603 kJ/mol.
• Second Ionization Enthalpy (IE₂): Approximately 1174 kJ/mol.
• Third Ionization Enthalpy (IE₃): Approximately 2417 kJ/mol.
  • Trend: Ytterbium has relatively low first and second ionization enthalpies due to the ease of removing the two valence 6s electrons. The third ionization enthalpy is significantly higher because it involves removing an electron from the stable, completely filled 4f¹⁴ subshell.

Electronegativity

• Pauling Scale Electronegativity: Approximately 1.1.
  • Trend: Ytterbium is an electropositive metal, possessing a low electronegativity, indicative of its tendency to lose electrons.

Electron Gain Enthalpy

• Value: Generally positive or close to zero.
  • Trend: As a metal, Ytterbium typically does not readily accept electrons. Its electron gain enthalpy is positive, meaning energy would be required to add an electron to a neutral Ytterbium atom.

Atomic Radius

• Value: Approximately 194 pm (metallic radius).
  • Trend: Ytterbium exhibits the typical lanthanide contraction effect across the series, though being at the end, its size is a result of the cumulative contraction.

Key Physical Properties

Density

• Value: 6.90 g/cm³ at 25 °C.

State

• At Room Temperature: Solid.

Color

• Silvery-white.

Melting Point

• Value: Approximately 819 °C.

Boiling Point

• Value: Approximately 1196 °C.