Chalk (disambiguation)

Chalk may refer to:

Surname

Magnesium carbonate

Magnesium carbonate, MgCO₃ (archaic name magnesia alba), is an inorganic salt that is a white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals.

Forms

The most common magnesium carbonate forms are the anhydrous salt called magnesite (MgCO₃) and the di, tri, and pentahydrates known as barringtonite (MgCO₃·2 H₂O), nesquehonite (MgCO₃·3 H₂O), and lansfordite (MgCO₃·5 H₂O), respectively. Some basic forms such as artinite (MgCO₃·Mg(OH)₂·3 H₂O), hydromagnesite (4 MgCO₃·Mg(OH)₂·4 H₂O), and dypingite (4 MgCO₃· Mg(OH)₂·5 H₂O) also occur as minerals.

Magnesite consists of white trigonal crystals. The anhydrous salt is practically insoluble in water, acetone, and ammonia. All forms of magnesium carbonate react in acids. Magnesium carbonate crystallizes in the calcite structure where in Mg²⁺ is surrounded by six oxygen atoms. The dihydrate one has a triclinic structure, while the trihydrate has a monoclinic structure.

References to 'light' and 'heavy' magnesium carbonates actually refer to the magnesium hydroxy carbonates hydromagnesite and dypingite (respectively).

Chalk (military)

In military terminology, a chalk is a group of paratroopers or other soldiers that deploy from a single aircraft. A chalk often corresponds to a platoon-sized unit for air assault operations, or a company-minus-sized organization for airborne operations. For air transport operations, it can consist of up to a company-plus-sized unit. Oftentimes, a load of paratroopers in one aircraft, prepared for a drop, is also referred to as a stick.

The term was first coined in World War II for airborne troops during Operation Overlord, the Allied invasion of Europe. The aircraft flight number was placed on the troops' backs with chalk. It was later used during the Vietnam War, when it was common practice to number with chalk the sides of the helicopters involved in an operation. During the Battle of Mogadishu (1993), the battle plan called for four chalks from the 75th Ranger Regiment to fast rope down from hovering MH-60L Black Hawk helicopters around the target building. The rangers would then create a four-corner defensive perimeter. The plan failed as two of the Black Hawks were shot down, and the assault turned into a forced evacuation.

Velocifero

Velocifero is the fourth studio album by English electronic band Ladytron and their first to be released by Nettwerk. The album was made available on the iTunes Store as of 19 May 2008, followed by a physical release on 2 June in the United Kingdom and on 3 June elsewhere. Velocifero peaked at number seventy-five on the UK Albums Chart, becoming the band's second highest-charting album to date in the UK (after Gravity the Seducer reached number seventy-two in 2011). It was also their first album to chart on the US Billboard 200, reaching number 131.

According to band member Reuben Wu, "velocifero" literally means "bringer of speed", and is also the name of a classic retro-styled scooter. "Black Cat" and "Kletva" are both sung entirely in Bulgarian. "Kletva" (which means "oath") is a cover of a song from a solo album by Kiril Marichkov of Bulgarian rock band Shturtzite. Daniel Hunt provided additional vocals on "Versus".

Velocifero produced three singles: "Ghosts", "Runaway" and "Tomorrow".

Runaway (Janet Jackson song)

"Runaway" is a song recorded American singer Janet Jackson for her first greatest hits album, Design of a Decade: 1986–1996 (1995). Written and produced by Jackson and Jimmy Jam and Terry Lewis, the track was released as the album's lead single on August 29, 1995, by A&M Records.

Background and composition

"Runaway" was created as a duet with Jackson's brother Michael Jackson, but he chose "Scream" instead. "Runaway" blends hard pop-hip hop beats with influences from African and Asian music, and has a similar sound to her previous hits "Escapade" and "Whoops Now". Towards the end of the song, Jackson breaks the fourth wall with the lyric, "Ooh, didn't quite hit the note/That wasn't such a good time". Africa, Nairobi, Tuscany, Australia, Mexico, Spain, and Paris are mentioned in the song.

Chart performance

"Runaway" made Jackson the first female artist in Billboard's history to debut in the top ten of the Billboard Hot 100, entering at number six in September 1995. It eventually peaked at number three. It was certified gold by the Recording Industry Association of America (RIAA) and sold 800,000 copies domestically. The song also reached the top spot in Canada, in addition to being a top ten hit in the United Kingdom and Australia and a moderate success in continental Europe, reaching the top 30 in most countries.

Runaway (Tohoshinki song)

"Runaway / My Girlfriend (Yuchun from 東方神起)" is Tohoshinki's 18th Japanese single, released on February 13, 2008. The single is the second installment of the song "Trick" in the album T.

Track listing

CD

Release history

Charts

Oricon Sales Chart (Japan)

Korea Top 20 foreign albums & singles

References

External links