Science

Electrical switches are used to control the flow of electrical current in an electrical circuit. A "closed" switch enables electrical current to flow through the electrical circuit; "opening" a...

A ferrite bead is an electronic component which functions as a low-pass filter in many types of circuitry. Low-pass filters are designed to allow low frequency signals to pass but will attenuate...

Chemistry glassware is produced either through casting glass or blowing glass. In the casting process, the molten glass is poured into a mold, allowed to cool, and then removed from the mold....

The pulse energy of a laser is total energy contained in a single laser pulse.

Lanolin alcohol is a mixture of several alkyl alcohols, fatty acids and cholesterols. It has no discrete structure.

Flowers offer birds, insects and animals nectar and pollen as a nutrition source in return for help in pollination. Since flowers are rooted and can't move about, they benefit from their mobile...

Testosterone (C₁₉H₂₈O₂) is a steroid-hormone, or androgen, related to cholesterol. Its main functional group is its template of three 6-carbon rings and one...

Magnesium metal is that lightweight metal used in specialty alloys. When the metal reacts with oxygen, it produces the white powder magnesium oxide (MgO). Glycine (NH₂CH₂COOH) is...

NAND gates are a common logic element used in many electronic circuits. The most common configuration is a two-input NAND gate, although configurations with more inputs are common. A NAND gate can...

Organelles are sub-compartments of the cells of certain eukaryotes and prokaryotes, each dedicated to its own specific function. It is thought that some, such as mitochondria, may have evolved...

Greenhouse gases (GHGs) are gases that contribute to the "greenhouse" effect, in which heat becomes trapped within the earth's atmosphere and causes the temperature of the planet to rise. In an...

A pendulum consists of only a few components including a length of string or wire, a bob or some type of weight and a fixed point. They can be used to prove that the planet rotates on an axis. The...

Prostate specific-antigen (PSA) is a protein produced by the cells of the prostate. Small amounts of it circulate in the blood. When the prostate forms tumors, these antigens are found at higher...

The flesh eating disease (necrotizing fasciitis) is caused by the bacteria Streptococcus pyogenes. The disease causes serious damage to tissue, and it can lead to amputation and death if not...

Its easy to cook a hot dog without a mess and using two nails. 1. Hammer 2 nails thru a board a little less apart than the length of a winnie. 2. Remove 1 1/2"in. of the insulation from an...

You can measure the force of magnets if you have a gaussmeter, an electronic device with a read-out calibrated in units called gauss. Gaussmeters come in both handheld and benchtop styles.

A steam turbine is a mechanical device whose purpose is to convert thermal (or heat) energy into work. Thermal energy is the type of energy that manifests itself as an increase in temperature. The...

Viruses are microbes that require host cells for proliferation. A virus enters a host cell and inserts its genome into the nuclear DNA. It uses the host's replication process to create its own...

A hydrogen ion concentration in a solution results from the addition of an acid. Strong acids give a higher concentration of hydrogen ions than weak acids, and it is possible to calculate the...

Mercury thermometers, used in some science labs, require special safety precautions. Alcohol thermometers, though less dangerous, should still be handled carefully to avoid broken glass.

With the growing popularity of DVD recorders, medium-power laser diodes are more widely available. The 150 milliwatt (mW) devices record by burning tiny pits in a blank DVD. They can burn other...

Potassium Chlorate is a white, crystalline substance with molecular formula KClO3. It is commonly used as an oxidizing agent. It can also be used as a disinfectant, and is an ingredient in safety...

Melting point analysis provides easy identification of solid substances, such as benzoic acid, in the lab. Using a melting point device such as a Mel-Temp, students can observe the sharp melting...

A complex interconnected series of sugar molecules (saccharides) comprise starch molecules. To test for the presence of these polysaccharides (many sugar) structured starches you will need iodine....

Laser cutters are quick, accurate and silent. Controlled by computer, they can cut many materials at speeds up to 500 inches per minute. They've helped to reduce costs and improve speed of...

Enzymes, groups of proteins, are commonly isolated from tissue samples and purified for experimental use. The experimental methods can enable the understanding of cell function and metabolic...

Potassium permanganate is a highly toxic chemical and strong oxidizer that requires careful handling and disposal. The chemical can be ordered only by laboratories with certification for its use....

Wax flowers, also known as hoya flowers, are tropical, ornamental plants that bear star shaped flowers that are very fragrant. There are over 200 species of these perennial evergreens. Hoya...

Nearly 40 percent of the earth's land surface is composed of grassland ecosystems. Grasslands throughout the world are essential to the survival of plant, animal, and bird species. Grasslands also...

Bone is a living, changing tissue that protects our organs and works with our musculature system to allow us to move. Bone also stores minerals and is responsible for making all of our red and...

External respiration is part of a three-part process that includes external respiration, internal respiration and cellular respiration, which together constitute how we exchange gases with our...

Convolution is one of the most widely used operations in applied mathematics. It involves two distinct functions that, when combined, produce a third function deemed to be a modified structure of...

Drawing dinosaurs and animals can be exciting and challenging. The main problem in drawing dinosaurs is where to find one. Because they are extinct, the closest you can come to one is in a museum...

Benzalkonium chloride (BAK or BAC) is a mixture of chemically similar substances made from animal products and possessing this chemical...

Batteries can be connected together either in series or parallel configurations. A series arrangement creates a total voltage equal to the sum of voltage of all the batteries. Flashlight batteries...

Circuit breakers and fuses perform the same basic function, to automatically relieve an overloaded circuit. Circuit breakers do more and cost more. Fuses are simple and inexpensive. They each have...

A circuit breaker is a protective electrical device that opens a circuit when overloaded. Circuit breakers have replaced fuses in most home, commercial, and industrial electrical applications....

Potassium, an alkali metal (atomic number 19 on the periodic table of the elements), is a soft and very reactive metal, which gives up one electron to form compounds. It reacts violently with...

Atoms are made of protons, neutrons and electrons. There are approximately 90 different varieties of atoms called elements. These elements combine with each other to form millions of different...

Fungi are a large category of organisms that includes mushrooms, molds, yeasts and mildews. Scientists have identified about 80,000 species of fungi.

Glucose is a type of simple sugar needed for energy by the red blood cells and the brain. The molecule helps construct and break down vitamins, sugars and proteins in the body. It is found in...

Any electrical circuit generates heat. This heat is the result of current flowing through a resistance, and this phenomenon is found in toasters, light bulbs and high-voltage power...

The urinary system is a network of filters, tubes and containers that cleanse the body of excess salts, fluids, waste and electrolytes that enter the body through food and liquids. The organs...

Cubic foot is a unit of volume used in the U.S. and several other countries. One cubic foot approximately corresponds to 0.028 of the cubic meter. The volume can be computed using the diameter...

In most of the world, household outlet voltage is 220 volts. In the United States and neighboring countries, however, household outlets run at 110 or 120 volts. This can pose a serious problem...

Methane exists as a gas and hexane in liquid form at room temperature because intermolecular forces affect the molecules of these substances differently.

The relative atomic mass is the ratio of an atom mass to 1/12 of the mass of an atom of carbon-12 (isotope 12). Isotopes have the same number of protons and hence the same atomic number, but they...

Keratin refers not to one particular substance but to a family of tough, fibrous proteins found in the animal kingdom. Keratin is present in hair, horn, hooves, beaks, shells, fingernails,...

Making the minute gigantic, the compound light microscope is one of the primary tools for any scientist doing research. It is a high quality instrument with many parts, each with a specific function.

Although human eyes cannot see the ultraviolet light emitted by black light bulbs, certain objects glow under black light. This occurs because those objects reflect that light back as part of the...