Chemical Sciences

Electrophilic Addition to Alkenes Mechanism Electrophilic addition to alkenes takes the following general form: nuc : = nucleophile E+ = electrophile Electrophilic addition to alkenes starts with the pi electrons attacking an electrophile, forming a carbocation on the most stable carbon. A nucleophile then attacks the carbocation to form the product. There are many different kinds of such addition, including: Hydroxylation Hydrogenation Halogenation Oxidative Cleavage Hydration Epoxidation Cyclopropanation Halohydrin Formation Clearly, there are numerous kinds of products that can be formed as a result of this mechanism. Orientation of Addition : Electrophilic Addition adds to give the Markovnikov Product, with the nucleophile added to the more highly substituted carbon. This is because the carbocation intermediate is significant

F Block Elements The long form of the periodic table is a tabular representation of all known elements. Elements are arranged in this table in the increasing order of their atomic number. We know that an atom is neutral due to the same number of electrons and protons therefore the atomic number of element provides the complete information about the electronic configuration of elements. On the basis of the valence shell configuration and position of valence electron in the element, the long form of the periodic table can be classified in 4 blocks. The s-block elements are placed in 1st and 2nd group on the table and called as alkali metal and alkaline earth metal. The p-block elements are placed from a 13th group to 18th in the periodic table. There are metals, metalloids and non-metals in this block. The d-block elements are placed from the 3rd group to 12th group of the periodic tables. They are also known as the transition elements. There are only metals in this block whic