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:lectrophilic 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.
Selective auditory attention or selective hearing is a type of selective attention and involves the auditory system of the nervous system.
By National Institute of Deafness and Other Hearing Disorders. Presbycusis is the loss of hearing that gradually occurs in most individuals as they grow older. Hearing loss is a common disorder associated with aging. About 30 to 35 percent of adults between the ages of 65 and 75 years have a hearing loss. It is estimated that 40 to 50 percent of people 75 and older have a hearing loss. The loss associated with presbycusis is usually greater for high-pitched sounds.