How do the physical properties of rust compare with the physical properties of iron and oxygen?

Rust is brittle, oxidized iron (oxygen reacted with the iron in the metal to produce rust). Meanwhile, iron is a metal and oxygen is a gas under room temperature conditions.

a) IRON = 7.86 g/cm³

b) RUST = 5.242 g/cm³

c) OXYGEN = 0.0014 g/cc

Rust is less dense than Iron but a gram of Iron will yield more than 1 gm of Rust, so we should observe a weight gain, and therefore an increase in density like in the rusted set of Nails.

a) IRON:

M.P = 1535 °C      B.P = 2862 °C

b) RUST:

M.P = 1370 °C       B.P = Decomposition at 3414 °C

c) OXYGEN:

M.P = -218 °C        B.P = -183 °C

a) IRON

Silvery gray

b) RUST

Orange red brown

c) OXYGEN

Colorless

a and b