Ice

At 917 kg/m³ it is 8% less dense than the water it came from, which is why it floats and why a bottle of water left in a freezer splits — that 8% expansion generates pressures no domestic container survives. Almost uniquely among solids, ice conducts heat four times better than its own liquid, so a layer of ice on a pond insulates far less well than it looks. It is also right at its melting point in ordinary use, which is why it creeps under load and why glaciers flow.

Properties

Density

917 kg/m³ — 0.92 g/cm³

Melting point

0 °C

Tensile strength

1–2 MPa

Young's modulus

9 GPa

Thermal conductivity

2.2 W/(m·K)

Hardness

1.5 Mohs

Thermal expansion

51 µm/(m·K)

Floats in water

Yes

Magnetic

No

What it is used for

• Cooling and food preservation
• Ice roads and winter construction
• Sculpture and event work
• Ice rinks and winter sport surfaces

How it compares

Does it rust?

Ice contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

Is it magnetic?

Ice is not a metal and has no ferromagnetic response.