Milwaukee M12 12-Volt Lithium-Ion Cordless 1400 Lumen ROCKET LED Stand Work Light (Tool-Only)

Twelve or 12 may refer to:

• 12 (number)
• December, the twelfth and final month of the year
• Dozen, a group of twelve.

Year 1400 (MCD) was a leap year starting on Thursday of the Julian calendar. The year 1400 was not a leap year in the Proleptic Gregorian calendar, it was a common year starting on Wednesday. The leap year began on a Thursday, and it ended on a Friday. The common year began on a Wednesday, and ended on a Wednesday, but the leap year ran from the Thursday to the Friday. The Wednesday at the beginning is January 1, the Wednesday at the end is December 31. It was the last year of the 14th century and the first year of the 15th century.

The term cordless is generally used to refer to electrical or electronic devices that are powered by a battery or battery pack and can operate without a power cord or cable attached to an electrical outlet to provide mains power, allowing greater mobility. The term "cordless" should not be confused with the term "wireless", although it often is in common usage, possibly because some cordless devices (e.g., cordless telephones) are also wireless. The term "wireless" generally refers to devices that use some form of energy (e.g., radio waves, infrared, ultrasonic, etc.) to transfer information or commands over a distance without the use of communication wires, regardless of whether the device gets its power from a power cord or a battery. The term "portable" is an even more general term and, when referring to electrical and electronic devices, usually means devices which are totally self-contained (e.g., have built-in power supplies, have no base unit, etc.) and which may also use wireless technology.

An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons.

A cation is a positively charged ion with fewer electrons than protons (e.g. K⁺ (potassium ion)) while an anion is a negatively charged ion with more electrons than protons. (e.g. Cl⁻ (chloride ion) and OH⁻ (hydroxide ion)). Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds.

If only a + or - is present, it indicates a +1 or –1 charge. To indicate a more severe charge, the number of additional or missing electrons is supplied, as seen in O₂^2– (negative charge, peroxide) and He²⁺ (positive charge, alpha particle).

Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.

Light, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 terahertz. The visible band sits adjacent to the infrared (with longer wavelengths and lower frequencies) and the ultraviolet (with shorter wavelengths and higher frequencies), called collectively optical radiation.

In physics, the term "light" may refer more broadly to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum, and polarization. Its speed in vacuum, 299792458 m/s, is one of the fundamental constants of nature. Like all types of electromagnetic radiation, visible light propagates by massless elementary particles called photons that represents the quanta of electromagnetic field, and can be analyzed as both waves and particles. The study of light, known as optics, is an important research area in modern physics.

The main source of natural light on Earth is the Sun. Historically, another important source of light for humans has been fire, from ancient campfires to modern kerosene lamps. With the development of electric lights and power systems, electric lighting has effectively replaced firelight.

Lithium (from Ancient Greek λίθος (líthos) 'stone') is a chemical element; it has symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. It exhibits a metallic luster. It corrodes quickly in air to a dull silvery gray, then black tarnish. It does not occur freely in nature, but occurs mainly as pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolytically from a mixture of lithium chloride and potassium chloride.

The nucleus of the lithium atom verges on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides. Because of its relative nuclear instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though its nuclei are very light: it is an exception to the trend that heavier nuclei are less common. For related reasons, lithium has important uses in nuclear physics. The transmutation of lithium atoms to helium in 1932 was the first fully human-made nuclear reaction, and lithium deuteride serves as a fusion fuel in staged thermonuclear weapons.

Lithium and its compounds have several industrial applications, including heat-resistant glass and ceramics, lithium grease lubricants, flux additives for iron, steel and aluminium production, lithium metal batteries, and lithium-ion batteries. These uses consume more than three-quarters of lithium production.

Lithium is present in biological systems in trace amounts. It has no established metabolic function in humans. Lithium-based drugs are useful as a mood stabilizer and antidepressant in the treatment of mental illness such as bipolar disorder.

Lumen may refer to:

• Lumen (unit), the SI unit of luminous flux
• Lumen (anatomy), the cavity or channel within a tubular structure
• Lumen (tech company), the health and wellness tech company
• Lumen (band), a Russian rock band
• Lumen (branding agency), a design and branding company headquartered in Milan, Italy
• The Lumen (Cleveland), a skyscraper in downtown Cleveland
• Lumen (website), a database of Digital Millennium Copyright Act takedown requests
• 141 Lumen, an asteroid
• Lumen Martin Winter (1908–1982), American artist
• Lumen Pierce, a fictional character in the television series Dexter
• Lumen Technologies, telecommunications company formerly known as CenturyLink
• Stellar Lumens, a cryptocurrency and payment network
• USS Lumen (AKA-30), a US Navy ship
• Lumen (dating app), a dating app for people over fifty
• Lumen, an office building in Warsaw, Poland, part of Złote Tarasy complex
• Lumen, an 1887 novel by Camille Flammarion

Milwaukee (locally mə-WAW-kee) is the most populous city in the U.S. state of Wisconsin and the seat of Milwaukee County. With a population of 577,222 at the 2020 census, Milwaukee is the 31st-most populous city in the United States and the fifth-most populous city in the Midwest. It is the central city of the Milwaukee metropolitan area, the 40th-most populous metro area in the U.S. with 1.57 million residents.

Milwaukee is an ethnically and culturally diverse city. However, it continues to be one of the most racially segregated cities, largely as a result of early-20th-century redlining. Its history was heavily influenced by German immigrants in the 19th century, and it continues to be a center for German-American culture, specifically becoming well known for its brewing industry. In recent years, Milwaukee has undergone several development projects. Major additions to the city since the turn of the 21st century include the Wisconsin Center, American Family Field, The Hop streetcar system, an expansion to the Milwaukee Art Museum, Milwaukee Repertory Theater, the Bradley Symphony Center, and Discovery World, as well as major renovations to the UW–Milwaukee Panther Arena. Fiserv Forum opened in late 2018, and hosts sporting events and concerts.

Milwaukee is rated as a "Sufficiency" city by the Globalization and World Cities Research Network, with a regional GDP of over $102 billion in 2020. Since 1968, Milwaukee has been home to Summerfest, a large music festival. Milwaukee is home to the Fortune 500 companies of Northwestern Mutual, Fiserv, WEC Energy Group, Rockwell Automation, and Harley-Davidson. It is also home to several colleges, including Marquette University, the Medical College of Wisconsin, Milwaukee School of Engineering, and University of Wisconsin–Milwaukee. The city is represented in two of the four major professional sports leagues—the Bucks of the NBA and the Brewers of MLB.

A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates back hundreds of millennia, have been observed using tools to make other tools.

Early human tools, made of such materials as stone, bone, and wood, were used for the preparation of food, hunting, the manufacture of weapons, and the working of materials to produce clothing and useful artifacts and crafts such as pottery, along with the construction of housing, businesses, infrastructure, and transportation. The development of metalworking made additional types of tools possible. Harnessing energy sources, such as animal power, wind, or steam, allowed increasingly complex tools to produce an even larger range of items, with the Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor.

By extension, concepts that support systematic or investigative thought are often referred to as "tools" or "toolkits".

The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI).

Work may refer to:

• Work (human activity), intentional activity people perform to support themselves, others, or the community
  • Manual labour, physical work done by humans
  • House work, housework, or homemaking
  • Working animal, an animal trained by humans to perform tasks
• Work (physics), the product of force and displacement
  • Work (electric field), the work done on a charged particle by an electric field
  • Work (thermodynamics), energy transferred by the system to its surroundings
• Creative work, a manifestation of creative effort
  • Work of art, an artistic creation of aesthetic value
• Career, an individual's journey through learning, work and other aspects of life
• Employment, a relationship between two parties where work is paid for