Explanation:
Limostone is a sedimentary rock composed mainly of calcium carbonate (CACO3),generally calcite,although it frequently has traces of magnesite (MGCO3)and others carbonates.
Answer: noble gases
Explanation: The elements whose valence shell is already filled is stable and thus don not lose or gain electron and thus do not react.
Halogen is the name given to fluorine family which have 5 valence electrons and thus easily gain electrons to attain stable configuration.
Alkaline earth metal is the name given to group 2 elements which have 2 valence electrons and thus easily lose 2 electrons to attain stable configuration.
Noble gases is the name given to group 18 elements which have 8 valence electrons and thus do not lose or gain electrons and thus is non reactive.
Alkali metals is the name given to group 1 elements which have 1 valence electrons and thus easily lose 1 electron to attain stable configuration.
Sc (neutral) [Ar] 3d1 4s2
Sc+ [Ar] 3d1 4s1
Sc2+ [Ar] 3d1
hope this helped!
Average rate of reaction of H2 over this time is calculated as
initial concentration of H2 minus final concentration of H2
That is
{(0.35mol/l -0.12mol/l) / 50 sec}= 4.6 x 10 ^-3 mol/l/sec