Silver (Ag)
Silver (Ag) is a transition metal with atomic number 47 and a standard atomic weight of 107.87. At room temperature it is a solid that melts at 962 °C and boils at 2,162 °C.
Silver key facts
Silver at a glance
Identity
| Symbol | Ag |
|---|---|
| Atomic number (Z) | 47 |
| Atomic weight | 107.87 ± 0.01 (CIAAW 2024) |
| Category | Transition metal |
| Group | 11 |
| Period | 5 |
| Block | d-block |
| CAS number | 7440-22-4 |
Atomic properties
| Electron configuration | [Kr] 4d10 5s1 Full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1 |
|---|---|
| Electrons per shell | 2, 8, 18, 18, 1 |
| Oxidation states | +1 Less common: -2, -1, 0, +2, +3 |
| Electronegativity (Pauling) | 1.93 |
| First ionisation energy | 7.576 eV (731 kJ/mol) 2nd: 21.484 eV · 3rd: 34.8 eV |
| Electron affinity | 1.302 eV |
| Atomic radius (empirical) | 160 pm |
| Covalent radius | 128 pm |
| Van der Waals radius | 211 pm |
Physical properties
| State at 25 °C | Solid |
|---|---|
| Melting point | 961.8 °C · 1,763.2 °F · 1,234.93 K |
| Boiling point | 2,162 °C · 3,923.6 °F · 2,435.15 K |
| Density | 10.5 g/cm³ |
| Specific heat capacity | 0.235 J/(g·K) |
| Thermal conductivity | 429 W/(m·K) |
| Crystal structure | Face-centred cubic |
Isotopes & abundance
| Natural occurrence | Primordial |
|---|---|
| Radioactive | No |
| Natural isotopes (abundance) | 107Ag 51.839%, 109Ag 48.161% |
| Stable isotopes | 3 |
| Known isotopes | 42 |
| Abundance in Earth's crust | 0.075 mg/kg |
| Abundance in seawater | 0.00004 mg/L |
Atomic weights: CIAAW Abridged Standard Atomic Weights 2024. Other properties: standard reference compilations, checked October 2026; predicted values are marked.
Silver electron configuration
Silver has 47 electrons. Written in short form, its ground-state configuration is [Kr] 4d10 5s1 — the electrons of the noble gas krypton, plus 4d10 5s1.Written out in full: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1.
An exception to the filling rule. The simple aufbau (Madelung) order predicts 5s2, 4d9, but silver actually has 5s1, 4d10. Half-filled and filled subshells, and the close energies of the outer orbitals, make this arrangement more stable.
Discovery and name
Prehistoric — Known since antiquity.
Anglo-Saxon seolfor; the symbol Ag is from Latin argentum.
Known for
The best electrical and thermal conductor of all metals. Used in jewellery, solar cells, electronics and as an antibacterial agent.
Isotopes of silver
Naturally occurring silver is a mix of 2 isotopes. Each has 47 protons; they differ in the number of neutrons:
| Isotope | Protons | Neutrons | Natural abundance | Stability |
|---|---|---|---|---|
| 107Ag | 47 | 60 | 51.839% | stable |
| 109Ag | 47 | 62 | 48.161% | stable |
42 isotopes of silver are known in our data set (half-lives as published in nuclear data tables).
Silver compared with group 11
The other elements in group 11, from top to bottom of the table:
| Element | Z | Atomic weight | Melting point | Boiling point | Density | Electronegativity |
|---|---|---|---|---|---|---|
| Copper | 29 | 63.546 | 1,085 °C | 2,560 °C | 8.96 g/cm³ | 1.9 |
| Silver | 47 | 107.87 | 962 °C | 2,162 °C | 10.5 g/cm³ | 1.93 |
| Gold | 79 | 196.97 | 1,064 °C | 2,836 °C | 19.3 g/cm³ | 2.54 |
| Roentgenium | 111 | [282] | — | — | 28.7 g/cm³ (pred.) | — |