Before 1937, scientists had not found element 43. Chemists predicted the
properties of element 43. How was it possible for chemists to predict these properties?

A drain cleaner is a chemical product that unblocks sewer pipes or clogged wastewater drains. The term may also refer to a mechanical device such as a plumber's snake, drain auger, toilet plunger, or similar device. Occasionally, the term is applied to a plumber or other individual who performs the drain cleaning and hygiene.A drain cleaner is a chemical product that unblocks sewer pipes or clogged wastewater drains. The term may also refer to a mechanical device such as a plumber's snake, drain auger, toilet plunger, or similar device. Occasionally, the term is applied to a plumber or other individual who performs the drain cleaning and hygiene.Chemical drain cleaners, plungers, handheld drain augers, air burst drain cleaners, and home remedy drain cleaners are typically applied to the problem of a clogged single drain, such as a sink, toilet, tub, or shower drain. An effective drain cleaner can remove soft obstructions (such as hair and grease) accumulating near the fixture's drain inlet.A drain cleaner is a chemical product that unblocks sewer pipes or clogged wastewater drains. The term may also refer to a mechanical device such as a plumber's snake, drain auger, toilet plunger, or similar device. Occasionally, the term is applied to a plumber or other individual who performs the drain cleaning and hygiene.Chemical drain cleaners, plungers, handheld drain augers, air burst drain cleaners, and home remedy drain cleaners are typically applied to the problem of a clogged single drain, such as a sink, toilet, tub, or shower drain. An effective drain cleaner can remove soft obstructions (such as hair and grease) accumulating near the fixture's drain inlet.If more than one plumbing fixture is clogged then electric drain cleaners, battery powered drain cleaners, sewer jetters or such mechanical devices are usually required to clear obstructions along the entire length of the drain piping system, that is, from fixture drain inlets through the main building drains and lateral piping outside the building to the collector sewer mains.A drain cleaner is a chemical product that unblocks sewer pipes or clogged wastewater drains. The term may also refer to a mechanical device such as a plumber's snake, drain auger, toilet plunger, or similar device. Occasionally, the term is applied to a plumber or other individual who performs the drain cleaning and hygiene.Chemical drain cleaners, plungers, handheld drain augers, air burst drain cleaners, and home remedy drain cleaners are typically applied to the problem of a clogged single drain, such as a sink, toilet, tub, or shower drain. An effective drain cleaner can remove soft obstructions (such as hair and grease) accumulating near the fixture's drain inlet.If more than one plumbing fixture is clogged then electric drain cleaners, battery powered drain cleaners, sewer jetters or such mechanical devices are usually required to clear obstructions along the entire length of the drain piping system, that is, from fixture drain inlets through the main building drains and lateral piping outside the building to the collector sewer mains.Each type of drain cleaner has advantages, disadvantages, and safety considerations as described below.