Chemistry · Ch 2 — p-Block Elements-I
Physical Properties
Physical Properties
Table 2.4 tabulates the core physical properties of the five group 14 elements. All five are solids at 293 K. Atomic number rises from 6 (carbon) to 82 (lead). Carbon has three well-known isotopes (¹²C, ¹³C and the radioactive ¹⁴C used in radiocarbon dating), while silicon, germanium, tin and lead each have one or two principal isotopes shown in the table. Every member has the outer configuration ns²np².
Atomic radius jumps sharply from carbon (1.70 Å) to silicon (2.10 Å) and then stays fairly level through germanium, tin and lead (2.02-2.17 Å) -- the same poor-shielding, d/f-electron pattern noted for ionisation enthalpy in Section 2.1.3. Density rises steeply down the group, from carbon's 3.51 g cm⁻³ to lead's 11.30 g cm⁻³. Carbon does not melt under ordinary conditions -- it sublimes at 4098 K -- while the remaining members …
| Property | Carbon | Silicon | Germanium | Tin | Lead |
|---|---|---|---|---|---|
| Physical state at 293 K | Solid | Solid | Solid | Solid | Solid |
| Atomic Number | 6 | 14 | 32 | 50 | 82 |
| Isotopes | ¹²C, ¹³C, ¹⁴C | ²⁸Si, ³⁰Si | ⁷³Ge, ⁷⁴Ge | ¹²⁰Sn | ²⁰⁸Pb |
| Atomic Mass (g mol⁻¹ at 293 K) | 12.01 | 28.09 | 72.63 | 118.71 | 207.2 |
| Electronic configuration | [He]2s²2p² | [Ne]3s²3p² | [Ar]3d¹⁰4s²4p² | [Kr]4d¹⁰5s²5p² | [Xe]4f¹⁴5d¹⁰6s²6p² |
| Atomic radius (Å) | 1.70 | 2.10 | 2.11 | 2.17 | 2.02 |
| Density (g cm⁻³ at 293 K) | 3.51 | 2.33 | 5.32 | 7.29 | 11.30 |