Which nuclide has a half-life that is less than one minute?
(1) cesium-137 (3) phosphorus-32
(2) francium-220 (4) strontium-90

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

answer; natural resources;