Silver (Ag)

Silver has the highest electrical and thermal conductivity of any element and the highest reflectivity in the visible spectrum, which is why it is used where performance matters more than cost. Its tarnish is not oxidation but silver sulfide, formed from traces of hydrogen sulfide in the air, which is why silver blackens faster near eggs, onions and rubber bands. Photography ran on silver halides for 150 years, and the collapse of film consumed less silver than expected only because solar panels took up the slack — a modern panel uses roughly 15 to 20 grams of silver paste.

Properties

Atomic number

47

Symbol

Ag

Standard atomic weight

107.87 u

Category

Transition metal

Group

11

Period

5

Block

d-block

Electron configuration

[Kr] 5s¹ 4d¹⁰

Electrons per shell

2, 8, 18, 18, 1

Melting point

1,234.93 K — 961.8 °C — 1763.2 °F

Boiling point

2,435 K — 2161.8 °C — 3923.3 °F

Density

10.501 g/cm³

Electronegativity

1.93 (Pauling)

Oxidation states

+1

Discovered

Known since antiquity

Electron configuration

Full

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d¹⁰

Noble gas shorthand

[Kr] 5s¹ 4d¹⁰

Shells

K: 2 · L: 8 · M: 18 · N: 18 · O: 1

What it is used for

• Solar panel contacts — now the single largest industrial use
• Electrical contacts in relays, switches and circuit breakers
• Brazing alloys for plumbing and refrigeration joints
• Antimicrobial wound dressings and catheter coatings
• Jewellery, cutlery and coinage

Anomalous electron configuration: [Kr] 5s¹ 4d¹⁰ rather than the predicted 5s² 4d⁹ — the same filled-d-subshell effect as copper and gold, the other two elements in group 11.

Neighbours in the table

Group 11

Elements in the same group share their outer electron count, which is why they behave similarly in reactions. Silver sits in group 11 with copper, gold, roentgenium.