Answer : The correct option is, (D)
Explanation :
Option A reaction :
It is a combustion reaction. A reaction in which a hydrocarbon react with the oxygen to give product as carbon dioxide and water.
Option B reaction :
It is a combination reaction. A reaction in which the two or more reactants react to give a product.
Option C reaction :
It is a decomposition reaction. A reaction in which a reactant decomposes to form two or more products.
Option D reaction :
It is a single displacement reaction. It is a reaction in which the more reactive element displace the less reactive element. In this reaction, most reactive element chlorine displaces the less reactive element bromine.
Hence, the correct option is, (D)
The elements whose electron configurations end with f electrons are in the Lanthanide and Actinide series: those long series at the bottom of the Periodic Table (see image).
The atoms are adding electrons into f orbitals, but the f electrons are not always the last electrons in the electron configuration.
For example, the electron configuration of Eu is [Xe]6s²4f⁷, but that of Gd
is [Xe] 6s²4f⁷5d.
I have blocked off in <em>red</em> all the <em>exceptions</em> like Gd.
