beryllium foil

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Beryllium (Be) is a brittle, steel-gray alkaline earth metal.     Beryllium is strong, lightweight, and has a modulus of elasticity 50% greater than steel.   It has non-magnetic properties and has higher specific heat than any metal.      Beryllium retains excellent properties at elevated and cryogenic temperatures, making this fascinating metal an ideal thermal conductor.      Because of its low density and high thermal conductivity, beryllium has many applications in the aerospace and military industries.      It is frequently used as a material in acoustic applications for its damping properties and high stiffness-to-weight ratio.