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123456789101112131415161718 1234567 57–71 Lanthanides89–103 Actinides
Side by side
Same properties. Different possibilities.
| Property | C Carbon | Si Silicon |
|---|---|---|
| At a glance | ||
| Atomic number | C 6 | Si 14 |
| Atomic mass | C 12.011 u | Si 28.085 u |
| Element family | C Nonmetals | Si Metalloids |
| Period | C 2 | Si 3 |
| Group | C 14 | Si 14 |
| State at room temperature | C solid | Si solid |
| Atomic structure | ||
| Full electron configuration | C 1s, 2 electrons; 2s, 2 electrons; 2p, 2 electrons; Differs across selected elements. | Si 1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; Differs across selected elements. 3s, 2 electrons; Differs across selected elements. 3p, 2 electrons; Differs across selected elements. |
| Electrons per shell | C 2, 4 | Si 2, 8, 4 |
| Electronegativity | C 2.55 (Pauling) | Si 1.9 (Pauling) |
| First ionization energy | C 1,087 kJ/mol | Si 787 kJ/mol |
| Electron affinity | C 154 kJ/mol | Si 134 kJ/mol |
| Atomic radius | C 77 pm | Si 111 pm |
| Physical properties | ||
| Density | C 2.26 g/cm³ | Si 2.33 g/cm³ |
| Melting point | C 3,823 K | Si 1,687 K |
| Boiling point | C 4,300 K | Si 3,173 K |
| Molar heat capacity | C 8.517 J/(mol·K) | Si 19.789 J/(mol·K) |
| Bonding type | C covalent network | Si metallic |
| Explore further | View Carbon | View Silicon |
Temperatures are in kelvin. Missing measurements are shown as “Not available”; they are never treated as zero. Atomic masses for elements without stable isotopes use a representative isotope.