Tin, lead and their alloys, due to their low melting temperatures and wide availability, are the most commonly used solder materials. In fact, lead has been used as a soldering metal for water pipes (also made of lead) even in Roman times, hence the scientific name for lead, Plumbum. Mechanical Properties.
hearing impairment - impairment of the sense of hearing. hearing disorder. disability, disablement, handicap, impairment - the condition of being unable to perform as a consequence of physical or mental unfitness; reading disability; hearing impairment. deafness, hearing loss - partial or complete loss of hearing.
IDEA definition of speech or language impairments. a communication disorder such as stuttering, impaired articulation, a language impairment, or a voice impairment, which adversely affect a child's educational performance. IDEA definition of physical disabilities. a severe orthopedic impairment that adversely affects a child's educational performance. The term includes impairments caused by congenital anomaly, impairments caused by disease, and impairments from other causes.