-- when you cool them, their electrical resistance decreases. -- If you make them even colder, their resistance decreases more. -- If you make them even colder, their resistance decreases more. -- If you make them even colder, their resistance decreases more.
-- If you keep making them colder, their resistance keeps decreasing, but it never completely disappears, no matter how cold you make them.
But with a few surprising substances, called 'superconductors' . . .
-- when you cool them, their electrical resistance decreases. -- If you make them even colder, their resistance decreases more. -- If you make them even colder, their resistance decreases more. -- If you make them even colder, their resistance decreases more.
-- If you keep making them colder, then suddenly, at some magic temperature, their resistance COMPLETELY disappears. It doesn't just become small, and it doesn't just become too small to measure. It becomes literally totally and absolutely ZERO.
If you start a current flowing in a superconducting wire, for example, you can connect the ends of the wire together, and the current keeps flowing around and around in it, for months or years. As long as you keep the loop cold enough, the current never decreases, because the superconducting wire has totally ZERO resistance.
Did somebody say "What's this good for ? What can you do with it ?"
1). Every CT-scan machine and every MRI machine needs many powerful magnets to do its thing. They are all electromagnets, with coils of superconducting wire, enclosed in containers full of liquid helium. Yes, it's complicated and expensive. But it turns out to be simpler and cheaper than using regular electromagnets, with coils of regular plain old copper wire, AND the big power supplies that would be needed to keep them going.
2). Resistance in wire means that when current flows through it, energy is lost. The long cables from the power-generating station to your house have resistance, so energy is lost on the way from the generating station to your house. That lost energy is energy that the electric company can't sell, because they can't deliver it to customers.
There are plans to build superconducting cables to carry electric power from the producers to the customers. The cables will be hollow pipes, with liquid helium or liquid hydrogen inside to keep them cold, and something on the outside to insulate them from the warmth outside. Yes, they'll be complicated and expensive. But they'll have ZERO resistance, so NO energy will be lost on its way from the generating stations to the customers. The power companies think they can build superconducting 'transmission lines' that will cost less than the energy that's being lost now, with regular cables.
Analytical chemistry studies and uses instruments and methods used to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes
Chemical engineers use chemistry and engineering to turn raw materials into usable products, such as medicine, petrochemicals, and plastics on a large-scale, industrial setting. They are also involved in waste management and research. ... They may be involved in designing and constructing plants as a project engineer.
A healthcare scientist or medical scientist is a scientist working in any of a number of health related disciplines. Healthcare scientists may work directly for health service providers, or in academia or industry.
Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and criminal procedure.
Research scientists are responsible for designing, undertaking and analysing information from controlled laboratory-based investigations, experiments and trials. You could work for government laboratories, environmental organisations, specialist research organisations or universities.
Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants.
A medicinal or pharmaceutical chemist researches and creates chemical compounds for use as drugs. By applying chemical research techniques to isolate natural healing agents or develop artificial ones, these chemists play a vital role in the pharmaceutical industry.
Nuclear chemists conduct basic, applied, or theoretical research. They often work in laboratories and may be responsible for operating, maintaining, and repairing state-of-the-art instrumentation.
Some industrial chemists work to improve product efficiency or to create better building materials, plastics, textiles, or petroleum products. They may help to set new industry standards, improve production techniques, and increase the effectiveness of various chemical processes.
Derivatization means adding fluorescent labels or combining the analyte with chiral reagents or other chemicals to increase detectability.
Some analytes must be derivatized to increase their column retention or detectability.
Retention time can be referred to as the amount of time a solute spends in the stationary and mobile phases of a column.
Detectability is the ability of an analyte to get detected in the mobile phase of chromatography.
The refractometer, fluorescence detector, and UV detector are the three most popular liquid chromatography detectors. These detectors increase the detectability.
For derivatization, the fluorescence detector are used.
There is a 1:1 molar ratio between magnesium and magnesium chloride. Magnesium has a molar mass of 24.31g/mol.
Explanation:
If you begin with 25.0 g of magnesium, how many moles of magnesium oxide will ... g C9H8O4. Now calculate percent yield. % yield = actual theoretical. × 100 =.
