Why is it possible for an active metal like aluminum to be useful as a structural metal?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

Word equation for k(s) +h2o(l) yield koh (aq) + h2

Which statement is true according to the kinetic theory? a. molecules of different gases with the same mass and temperature always have the same average density. b. molecules of different gases with the same mass and temperature always have the same average volume. c. molecules of different gases with the same mass and temperature always have the same pressure. d. molecules of different gases with the same mass and temperature always have the same molecular mass. e. molecules of different gases with the same mass and temperature always have the same average kinetic energy.