Tungsten (W)

Atomic Structure of Tungsten (W)

Tungsten (W), with atomic number 74, is a d-block transition element.

Atomic Number (Z): 74 (Indicates 74 protons and 74 electrons in a neutral atom).
Average Atomic Mass: 183.84 u.
Protons: 74
Electrons: 74
Neutrons: For its most abundant isotope, W-184, the number of neutrons is 184 - 74 = 110.
Atomic Radius (Covalent): Approximately 139 pm.

The electronic configuration of Tungsten (W) describes the arrangement of electrons in its atomic orbitals.

Noble Gas Core Configuration: [Xe] 4f¹⁴ 5d⁴ 6s²
Shell-wise Electron Distribution:
- K-shell (n=1): 2 electrons
- L-shell (n=2): 8 electrons
- M-shell (n=3): 18 electrons
- N-shell (n=4): 32 electrons (filled 4s, 4p, 4d, 4f orbitals)
- O-shell (n=5): 12 electrons (5s², 5p⁶, 5d⁴)
- P-shell (n=6): 2 electrons (6s²)
- This distribution (2, 8, 18, 32, 12, 2) illustrates the filling of electron shells from the innermost to the outermost.

Tungsten’s position in the periodic table (Group 6, Period 6, d-block) dictates its periodic properties.

First Ionization Enthalpy: Approximately 770 kJ/mol.
Trend Explanation: As a transition metal, Tungsten has a relatively high ionization enthalpy compared to s-block elements due to its higher nuclear charge and smaller atomic size. The presence of filled 4f orbitals leads to poor shielding, causing an effective increase in nuclear charge (lanthanoid contraction effect), which further contributes to its higher ionization energy compared to its lighter congeners in the 5d series.

Pauling Scale Electronegativity: Approximately 2.36.
Trend Explanation: Tungsten is among the more electronegative transition metals. Its relatively high electronegativity is consistent with its position in the d-block, where increasing nuclear charge and incomplete shielding by d and f electrons enhance the attraction for shared electrons.

Value: Generally positive or close to zero for metals. Specific values for Tungsten are not typically reported as it does not readily accept electrons to form anions.
Trend Explanation: Metals typically have a positive electron gain enthalpy, meaning energy is required to add an electron to a neutral gaseous atom. This is because metals tend to lose electrons rather than gain them.

Covalent Atomic Radius: Approximately 139 pm.
Trend Explanation: The atomic radius of Tungsten is influenced by the lanthanoid contraction. Due to the poor shielding effect of the 4f electrons, the effective nuclear charge experienced by the outermost electrons is significantly increased. This causes a contraction in the atomic and ionic radii of the 5d transition series elements, making Tungsten’s atomic radius comparable to that of Molybdenum (its congener in the 4d series) rather than significantly larger, as would be expected down a group.

Tungsten exhibits several unique and extreme physical properties.