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Apollo 11 | Moonwalk camera | Moonwalk camera
The Hasselblad camera used during the moonwalk was thought to be lost or left on the Moon surface. |
Apollo 11 | Lunar Module ''Eagle'' memorabilia | Lunar Module Eagle memorabilia
In 2015, after Armstrong died in 2012, his widow contacted the National Air and Space Museum to inform them she had found a white cloth bag in one of Armstrong's closets. The bag contained various items, which should have been left behind in the Lunar Module Eagle, including the 16mm D... |
Apollo 11 | Anniversary events | Anniversary events |
Apollo 11 | <span id="40th anniversary events"></span>40th anniversary | 40th anniversary
thumb|Columbia at the Mary Baker Engen Restoration Hangar
On July 15, 2009, Life.com released a photo gallery of previously unpublished photos of the astronauts taken by Life photographer Ralph Morse prior to the Apollo 11 launch. From July 16 to 24, 2009, NASA streamed the original mission audio on... |
Apollo 11 | 50th anniversary | 50th anniversary
On June 10, 2015, Congressman Bill Posey introduced resolution H.R. 2726 to the 114th session of the United States House of Representatives directing the United States Mint to design and sell commemorative coins in gold, silver and clad for the 50th anniversary of the Apollo 11 mission. On January 2... |
Apollo 11 | Films and documentaries | Films and documentaries
Footprints on the Moon, a 1969 documentary film by Bill Gibson and Barry Coe
Moonwalk One, a 1971 documentary film by Theo Kamecke
Apollo 11: As It Happened, a 1994 six-hour documentary on ABC News' coverage of the event
First Man, 2018 film by Damien Chazelle based on the 2005 James R. Ha... |
Apollo 11 | See also | See also
List of species that have landed on the Moon
List of photographs considered the most important |
Apollo 11 | References | References |
Apollo 11 | Notes | Notes |
Apollo 11 | Citations | Citations
In some of the following sources, times are shown in the format hours:minutes:seconds (e.g. 109:24:15), referring to the mission's Ground Elapsed Time (GET), based on the official launch time of July 16, 1969, 13:32:00 UTC (000:00:00 GET). |
Apollo 11 | Sources | Sources
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Apollo 11 | External links | External links
"Apollo 11 transcripts" at Spacelog
Apollo 11 in real time
Apollo 11 Press Conference filmed by KPRC-TV at Texas Archive of the Moving Image
Apollo 11 and 13 Checklists at The Museum of Flight Digital Collections.
Apollo 11, 12, and 14 Traverses, at the Lunar and Planetary Institute |
Apollo 11 | Multimedia | Multimedia
Remastered videos of the original landing.
Dynamic timeline of lunar excursion. Lunar Reconnaissance Orbiter Camera
The Eagle Has Landed: The Flight of Apollo 11 (1969) (transcript) from US National Archives (via YouTube)
Apollo 11 Restored EVA Part 1 (1hour of restored footage)
Apollo 11: As They ... |
Apollo 11 | Table of Content | Short description, Background, Personnel, Prime crew, Backup crew, Support crew, Capsule communicators, Flight directors, Other key personnel, Preparations, Insignia, Call signs, Mementos, Site selection, First-step decision, Pre-launch, Mission, Launch and flight to lunar orbit, Lunar descent, Landing, Lunar surface o... |
Apollo 8 | Short description | Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave Earth's gravitational sphere of influence, and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing and then returned to Earth. The three astronauts—Frank Borman, James Lovell, and William Anders—were ... |
Apollo 8 | Background | Background
In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union. On October 4, 1957, the Soviet Union launched Sputnik 1, the first artificial satellite. This unexpected success stoked fears and imaginations around the world. It not only demonst... |
Apollo 8 | Framework | Framework |
Apollo 8 | Prime crew | Prime crew
The initial crew assignment of Frank Borman as Commander, Michael Collins as Command Module Pilot (CMP) and William Anders as Lunar Module Pilot (LMP) for the third crewed Apollo flight was officially announced on November 20, 1967. Collins was replaced by Jim Lovell in July 1968, after suffering a cervical... |
Apollo 8 | Backup crew | Backup crew
The backup crew assignment of Neil Armstrong as Commander, Lovell as CMP, and Buzz Aldrin as LMP for the third crewed Apollo flight was officially announced at the same time as the prime crew. When Lovell was reassigned to the prime crew, Aldrin was moved to CMP, and Fred Haise was brought in as backup LMP... |
Apollo 8 | Support personnel | Support personnel
During Projects Mercury and Gemini, each mission had a prime and a backup crew. For Apollo, a third crew of astronauts was added, known as the support crew. The support crew maintained the flight plan, checklists, and mission ground rules, and ensured that the prime and backup crews were apprised of ... |
Apollo 8 | Mission insignia and callsign | Mission insignia and callsign
thumb|Apollo 8 space-flown silver Robbins medallion
The triangular shape of the insignia refers to the shape of the Apollo CM. It shows a red figure8 looping around the Earth and Moon to reflect both the mission number and the circumlunar nature of the mission. On the bottom of the8 are ... |
Apollo 8 | Preparations | Preparations |
Apollo 8 | Mission schedule | Mission schedule
On September 20, 1967, NASA adopted a seven-step plan for Apollo missions, with the final step being a Moon landing. Apollo4 and Apollo6 were "A" missions, tests of the SaturnV launch vehicle using an uncrewed Block I production model of the command and service module (CSM) in Earth orbit. Apollo5 was... |
Apollo 8 | Saturn V redesign | Saturn V redesign
The Saturn V rocket used by Apollo8 was designated AS-503, or the "03rd" model of the SaturnV ("5") rocket to be used in the Apollo-Saturn ("AS") program. When it was erected in the Vehicle Assembly Building on December 20, 1967, it was thought that the rocket would be used for an uncrewed Earth-orbi... |
Apollo 8 | Mission | Mission |
Apollo 8 | Parameter summary | Parameter summary
thumb|upright=3.0|Mission profile
As the first crewed spacecraft to orbit more than one celestial body, Apollo8's profile had two different sets of orbital parameters, separated by a translunar injection maneuver. Apollo lunar missions would begin with a nominal circular Earth parking orbit. Apollo... |
Apollo 8 | Launch and trans-lunar injection | Launch and trans-lunar injection
thumb|Apollo 8 launch
Apollo 8 was launched at 12:51:00 UTC (07:51:00 Eastern Standard Time) on December 21, 1968, using the Saturn V's three stages to achieve Earth orbit. The S-IC first stage landed in the Atlantic Ocean at , and the S-II second stage landed at . The S-IVB third sta... |
Apollo 8 | Lunar trajectory | Lunar trajectory
Lovell's main job as Command Module Pilot was as navigator. Although Mission Control normally performed all the navigation calculations, it was necessary to have a crew member adept at navigation so that the crew could return to Earth in case communication with Mission Control was lost. Lovell navigat... |
Apollo 8 | Lunar sphere of influence | Lunar sphere of influence
thumb|left|This photograph of the Moon was taken from Apollo8 at a point above 70 degrees east longitude.
At about 55 hours and 40 minutes into the flight, and 13 hours before entering lunar orbit, the crew of Apollo8 became the first humans to enter the gravitational sphere of influence of ... |
Apollo 8 | Lunar orbit | Lunar orbit
The SPS was ignited at 69 hours, 8minutes, and 16 seconds after launch and burned for 4minutes and 7seconds, placing the Apollo8 spacecraft in orbit around the Moon. The crew described the burn as being the longest four minutes of their lives. If the burn had not lasted exactly the correct amount of time, ... |
Apollo 8 | ''Earthrise'' and Genesis broadcast | Earthrise and Genesis broadcast
thumb|The Earthrise image
thumb|Apollo 8's 1968 Christmas Eve broadcast and reading from the Book of Genesis
When the spacecraft came out from behind the Moon for its fourth pass across the front, the crew witnessed an "Earthrise" in person for the first time in human history. NASA's Lu... |
Apollo 8 | Unplanned manual realignment | Unplanned manual realignment
Later, Lovell used some otherwise idle time to do some navigational sightings, maneuvering the module to view various stars by using the computer keyboard. He accidentally erased some of the computer's memory, which caused the inertial measurement unit (IMU) to contain data indicating that... |
Apollo 8 | Cruise back to Earth and reentry | Cruise back to Earth and reentry
thumb|left|Reentry, December 27, 1968, photographed from a KC-135 Stratotanker at 40,000 feet|alt=White streaks of light, with bright spots on the right side of them, fill the bottom of the frame. A larger yellow-tinted sphere with a streak is in the center of the frame. The background... |
Apollo 8 | Legacy | Legacy |
Apollo 8 | Historical importance | Historical importance
Apollo 8 came at the end of 1968, a year that had seen much upheaval in the United States and most of the world. Even though the year saw political assassinations, political unrest in the streets of Europe and America, and the Prague Spring, Time magazine chose the crew of Apollo8 as its Men of t... |
Apollo 8 | Spacecraft location | Spacecraft location
In January 1970, the spacecraft was delivered to Osaka, Japan, for display in the U.S. pavilion at Expo '70. It is now displayed at the Chicago Museum of Science and Industry, along with a collection of personal items from the flight donated by Lovell and the space suit worn by Frank Borman. Jim Lo... |
Apollo 8 | In popular culture | In popular culture
Apollo 8's historic mission has been depicted and referred to in several forms, both documentary and fiction. The various television transmissions and 16 mm footage shot by the crew of Apollo8 were compiled and released by NASA in the 1969 documentary Debrief: Apollo8, hosted by Burgess Meredith. De... |
Apollo 8 | See also | See also
Apollo 8 (book)
List of missions to the Moon |
Apollo 8 | Notes | Notes |
Apollo 8 | References | References |
Apollo 8 | Bibliography | Bibliography
|
Apollo 8 | External links | External links
"Apollo 8" at Encyclopedia Astronautica
Article about the 40th anniversary of Apollo8
Multimedia
Apollo 8: Go for TLI 1969 NASA film at the Internet Archive
Debrief: Apollo 8 1969 NASA film at the Internet Archive
"Apollo 07 and 08 16mm Onboard Film (1968)" raw footage taken from Apollos 7and8 at... |
Apollo 8 | Table of Content | Short description, Background, Framework, Prime crew, Backup crew, Support personnel, Mission insignia and callsign, Preparations, Mission schedule, Saturn V redesign, Mission, Parameter summary, Launch and trans-lunar injection, Lunar trajectory, Lunar sphere of influence, Lunar orbit, ''Earthrise'' and Genesis broadc... |
Astronaut | short description | thumb|NASA astronaut Bruce McCandless II using a Manned Maneuvering Unit outside on shuttle mission STS-41-B in 1984
An astronaut (from the Ancient Greek (), meaning 'star', and (), meaning 'sailor') is a person trained, equipped, and deployed by a human spaceflight program to serve as a commander or crew member of ... |
Astronaut | Definition | Definition
upright|thumb|Alan Shepard aboard Freedom 7 (1961)
The criteria for what constitutes human spaceflight vary, with some focus on the point where the atmosphere becomes so thin that centrifugal force, rather than aerodynamic force, carries a significant portion of the weight of the flight object. The (FAI)... |
Astronaut | Terminology | Terminology
In 1959, when both the United States and Soviet Union were planning, but had yet to launch humans into space, NASA Administrator T. Keith Glennan and his Deputy Administrator, Hugh Dryden, discussed whether spacecraft crew members should be called astronauts or cosmonauts. Dryden preferred "cosmonaut", on ... |
Astronaut | Astronaut | Astronaut
thumb|right|The first sixteen NASA astronauts to be selected, February 1963. Back row: White, McDivitt, Young, See, Conrad, Borman, Armstrong, Stafford, Lovell. Front row: Cooper, Grissom, Carpenter, Schirra, Glenn, Shepard, Slayton.
A professional space traveler is called an astronaut. The first known use o... |
Astronaut | Cosmonaut | Cosmonaut
thumb|The first eleven Soviet cosmonauts to fly, July 1965. Back row, left to right: Leonov, Titov, Bykovsky, Yegorov, Popovich; front row: Komarov, Gagarin, Tereshkova, Nikolayev, Feoktistov, Belyayev.
By convention, an astronaut employed by the Russian Federal Space Agency (or its predecessor, the Soviet s... |
Astronaut | Taikonaut | Taikonaut
thumb|The first Chinese taikonauts on a 2010 Somalia stamp
In Chinese, the term (, "cosmos navigating personnel") is used for astronauts and cosmonauts in general, while (, "navigating celestial-heaven personnel") is used for Chinese astronauts. Here, (, literally "heaven-navigating", or spaceflight) is s... |
Astronaut | Other terms | Other terms
With the rise of space tourism, NASA and the Russian Federal Space Agency agreed to use the term "spaceflight participant" to distinguish those space travelers from professional astronauts on missions coordinated by those two agencies.
thumb|right|Finnish American astronaut Timothy Kopra
While no nation ot... |
Astronaut | Space travel milestones | Space travel milestones
thumb|upright=0.667|Yuri Gagarin, first human in space (1961)
thumb|upright=0.667|Valentina Tereshkova, first woman in space (1963)
thumb|upright=0.667|Neil Armstrong, first human to walk on the Moon (1969)
thumb|upright=0.667|Vladimír Remek, a Czechoslovak who became the first non-American and... |
Astronaut | Age milestones | Age milestones
The youngest person to reach space is Oliver Daemen, who was 18 years and 11 months old when he made a suborbital spaceflight on Blue Origin NS-16. Daemen, who was a commercial passenger aboard the New Shepard, broke the record of Soviet cosmonaut Gherman Titov, who was 25 years old when he flew Vostok ... |
Astronaut | Duration and distance milestones | Duration and distance milestones
The longest time spent in space was by Russian Valeri Polyakov, who spent 438 days there.
As of 2006, the most spaceflights by an individual astronaut is seven, a record held by both Jerry L. Ross and Franklin Chang-Diaz. The farthest distance from Earth an astronaut has traveled was , ... |
Astronaut | Civilian and non-government milestones | Civilian and non-government milestones
The first civilian in space was Valentina Tereshkova aboard Vostok 6 (she also became the first woman in space on that mission).
Tereshkova was only honorarily inducted into the USSR's Air Force, which did not accept female pilots at that time. A month later, Joseph Albert Walker ... |
Astronaut | Self-funded travelers | Self-funded travelers
The first person to fly on an entirely privately funded mission was Mike Melvill, piloting SpaceShipOne flight 15P on a suborbital journey, although he was a test pilot employed by Scaled Composites and not an actual paying space tourist. Jared Isaacman was the first person to self-fund a mission... |
Astronaut | Training | Training
right|thumb|upright|Elliot See during water egress training with NASA (1965)
The first NASA astronauts were selected for training in 1959. Early in the space program, military jet test piloting and engineering training were often cited as prerequisites for selection as an astronaut at NASA, although neither J... |
Astronaut | NASA candidacy requirements | NASA candidacy requirements
The candidate must be a citizen of the United States.
The candidate must complete a master's degree in a STEM field, including engineering, biological science, physical science, computer science or mathematics.
The candidate must have at least two years of related professional experience... |
Astronaut | Mission Specialist Educator | Mission Specialist Educator
Applicants must have a bachelor's degree with teaching experience, including work at the kindergarten through twelfth grade level. An advanced degree, such as a master's degree or a doctoral degree, is not required, but is strongly desired.
Mission Specialist Educators, or "Educator Astron... |
Astronaut | Health risks of space travel | Health risks of space travel
thumb|right|Gennady Padalka performing ultrasound on Michael Fincke during ISS Expedition 9
Astronauts are susceptible to a variety of health risks including decompression sickness, barotrauma, immunodeficiencies, loss of bone and muscle, loss of eyesight, orthostatic intolerance, sleep di... |
Astronaut | Food and drink | Food and drink
thumb|right|Astronauts making and eating hamburgers on board the ISS, 2002
An astronaut on the International Space Station requires about mass of food per meal each day (inclusive of about packaging mass per meal).
Space Shuttle astronauts worked with nutritionists to select menus that appealed to th... |
Astronaut | Insignia | Insignia
thumb|upright|NASA Astronaut lapel pin
In Russia, cosmonauts are awarded Pilot-Cosmonaut of the Russian Federation upon completion of their missions, often accompanied with the award of Hero of the Russian Federation. This follows the practice established in the USSR where cosmonauts were usually awarded the t... |
Astronaut | Deaths | Deaths
thumb|Space Mirror Memorial
, eighteen astronauts (fourteen men and four women) have died during four space flights. By nationality, thirteen were American, four were Russian (Soviet Union), and one was Israeli.
, eleven people (all men) have died training for spaceflight: eight Americans and three Russians... |
Astronaut | See also | See also |
Astronaut | Explanatory notes | Explanatory notes |
Astronaut | References | References |
Astronaut | External links | External links
NASA: How to become an astronaut 101
List of International partnership organizations
Encyclopedia Astronautica: Phantom cosmonauts
collectSPACE: Astronaut appearances calendar
spacefacts Spacefacts.de
Manned astronautics: facts and figures
Astronaut Candidate Brochure online
Category:Sc... |
Astronaut | Table of Content | short description, Definition, Terminology, Astronaut, Cosmonaut, Taikonaut, Other terms, Space travel milestones, Age milestones, Duration and distance milestones, Civilian and non-government milestones, Self-funded travelers, Training, NASA candidacy requirements, Mission Specialist Educator, Health risks of space tr... |
A Modest Proposal | Short description | A Modest Proposal for Preventing the Children of Poor People from Being a Burthen to Their Parents or Country, and for Making Them Beneficial to the Publick, commonly referred to as A Modest Proposal, is a Juvenalian satirical essay written and published by Anglo-Irish writer and clergyman Jonathan Swift in 1729. The e... |
A Modest Proposal | Synopsis | Synopsis
thumb|A painting of Jonathan Swift
Swift's essay is widely held to be one of the greatest examples of sustained irony in the history of English literature. Much of its shock value derives from the fact that the first portion of the essay describes the plight of starving beggars in Ireland, so that the reader ... |
A Modest Proposal | Population solutions | Population solutions
George Wittkowsky argued that Swift's main target in A Modest Proposal was not the conditions in Ireland, but rather the can-do spirit of the times that led people to devise a number of illogical schemes that would purportedly solve social and economic ills.Wittkowsky, Swift’s Modest Proposal, p. 7... |
A Modest Proposal | Rhetoric | Rhetoric
Author Charles K. Smith argues that Swift's rhetorical style persuades the reader to detest the speaker and pity the Irish. Swift's specific strategy is twofold, using a "trap"Smith, Toward a Participatory Rhetoric, p. 135 to create sympathy for the Irish and a dislike of the narrator who, in the span of one s... |
A Modest Proposal | Influences | Influences
Scholars have speculated about which earlier works Swift may have had in mind when he wrote A Modest Proposal. |
A Modest Proposal | Tertullian's ''Apology'' | Tertullian's Apology
James William Johnson argues that A Modest Proposal was largely influenced and inspired by Tertullian's Apology: a satirical attack against early Roman persecution of Christianity. Johnson believes that Swift saw major similarities between the two situations.Johnson, Tertullian and A Modest Proposa... |
A Modest Proposal | Defoe's ''The Generous Projector'' | Defoe's The Generous Projector
It has also been argued that A Modest Proposal was, at least in part, a response to the 1728 essay The Generous Projector or, A Friendly Proposal to Prevent Murder and Other Enormous Abuses, By Erecting an Hospital for Foundlings and Bastard Children by Swift's rival Daniel Defoe. |
A Modest Proposal | Mandeville's ''Modest Defence of Publick Stews'' | Mandeville's Modest Defence of Publick Stews
Bernard Mandeville's Modest Defence of Publick Stews asked to introduce public and state-controlled bordellos. The 1726 paper acknowledges women's interests and—while not being a completely satirical text—has also been discussed as an inspiration for Jonathan Swift's title... |
A Modest Proposal | John Locke's ''First Treatise of Government'' | John Locke's First Treatise of Government
John Locke commented: "Be it then as Sir Robert says, that Anciently, it was usual for Men to sell and Castrate their Children. Let it be, that they exposed them; Add to it, if you please, for this is still greater Power, that they begat them for their Tables to fat and eat t... |
A Modest Proposal | Economic themes | Economic themes
Robert Phiddian's article "Have you eaten yet? The Reader in A Modest Proposal" focuses on two aspects of A Modest Proposal: the voice of Swift and the voice of the Proposer. Phiddian stresses that a reader of the pamphlet must learn to distinguish between the satirical voice of Jonathan Swift and the a... |
A Modest Proposal | "People are the riches of a nation" | "People are the riches of a nation"
At the start of a new industrial age in the 18th century, it was believed that "people are the riches of the nation", and there was a general faith in an economy that paid its workers low wages because high wages meant workers would work less.Phiddian, Have You Eaten Yet?, p. 4 Furth... |
A Modest Proposal | Public reaction | Public reaction
thumb|upright|Allen Bathurst, 1st Earl Bathurst
Swift's essay created a backlash within Georgian society after its publication. The work was aimed at the elite, and they responded in turn. Several prominent members of society wrote to Swift regarding the work. Lord Bathurst's letter (12 February 1729... |
A Modest Proposal | Modern usage | Modern usage
A Modest Video Game Proposal is the title of an open letter sent by activist/former attorney Jack Thompson on 10 October 2005.
The 2012 horror film Butcher Boys, written by the original The Texas Chain Saw Massacre scribe Kim Henkel, is said to be an updating of Jonathan Swift's A Modest Proposal. Henkel ... |
A Modest Proposal | See also | See also
Cannibalism in literature
Child cannibalism |
A Modest Proposal | Notes | Notes |
A Modest Proposal | References | References
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A Modest Proposal | External links | External links
A Modest Proposal (CELT)
A Modest Proposal (Gutenberg)
A Modest Proposal – Annotated text aligned to Common Core Standards
A Modest Proposal BBC Radio 4 In Our Time with Melvyn Bragg
'A modest proposal For preventing the children of poor people From being a Burthen to their Parents or the Country... |
A Modest Proposal | Table of Content | Short description, Synopsis, Population solutions, Rhetoric, Influences, Tertullian's ''Apology'', Defoe's ''The Generous Projector'', Mandeville's ''Modest Defence of Publick Stews'', John Locke's ''First Treatise of Government'', Economic themes, "People are the riches of a nation", Public reaction, Modern usage, See... |
Alkali metal | short description | ↓ Period 2 3 4 5 6 7 Legend
primordial element by radioactive decay
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, natrium and kalium; these are still the origins of the names for the e... |
Alkali metal | History | History
thumb|alt=A sample of petalite|Petalite, the lithium mineral from which lithium was first isolated
Sodium compounds have been known since ancient times; salt (sodium chloride) has been an important commodity in human activities. While potash has been used since ancient times, it was not understood for most of... |
Alkali metal | Occurrence | Occurrence |
Alkali metal | In the Solar System | In the Solar System
thumb|upright=2.5|Estimated abundances of the chemical elements in the Solar System. Hydrogen and helium are most common, from the Big Bang. The next three elements (lithium, beryllium, and boron) are rare because they are poorly synthesised in the Big Bang and also in stars. The two general trend... |
Alkali metal | On Earth | On Earth
thumb|upright|Spodumene, an important lithium mineral
The Earth formed from the same cloud of matter that formed the Sun, but the planets acquired different compositions during the formation and evolution of the Solar System. In turn, the natural history of the Earth caused parts of this planet to have diffe... |
Alkali metal | Properties | Properties |
Alkali metal | Physical and chemical | Physical and chemical
The physical and chemical properties of the alkali metals can be readily explained by their having an ns1 valence electron configuration, which results in weak metallic bonding. Hence, all the alkali metals are soft and have low densities, melting and boiling points, as well as heats of sublimat... |
Alkali metal | Lithium | Lithium
The chemistry of lithium shows several differences from that of the rest of the group as the small Li+ cation polarises anions and gives its compounds a more covalent character. Lithium and magnesium have a diagonal relationship due to their similar atomic radii, so that they show some similarities. For examp... |
Alkali metal | Francium | Francium
Francium is also predicted to show some differences due to its high atomic weight, causing its electrons to travel at considerable fractions of the speed of light and thus making relativistic effects more prominent. In contrast to the trend of decreasing electronegativities and ionisation energies of the alk... |
Alkali metal | Nuclear | Nuclear
+Primordial isotopes of the alkali metals Z Alkali metal Stable Decaysunstable: italicsodd–odd isotopes coloured pink 3 lithium 2 — 11 sodium 1 — 19 potassium 2 1 37 rubidium 1 1 55 caesium 1 — 87 francium — — No primordial isotopes( is a radi... |
Alkali metal | Periodic trends | Periodic trends
The alkali metals are more similar to each other than the elements in any other group are to each other. For instance, when moving down the table, all known alkali metals show increasing atomic radius, decreasing electronegativity, increasing reactivity, and decreasing melting and boiling points as we... |
Alkali metal | Atomic and ionic radii | Atomic and ionic radii
thumb|250px|Effective nuclear charge on an atomic electron
The atomic radii of the alkali metals increase going down the group. Because of the shielding effect, when an atom has more than one electron shell, each electron feels electric repulsion from the other electrons as well as electric att... |
Alkali metal | First ionisation energy | First ionisation energy
thumb|upright=2.7|Periodic trend for ionisation energy: each period begins at a minimum for the alkali metals, and ends at a maximum for the noble gases. Predicted values are used for elements beyond 104.
The first ionisation energy of an element or molecule is the energy required to move the ... |
Alkali metal | Reactivity | Reactivity
The reactivities of the alkali metals increase going down the group. This is the result of a combination of two factors: the first ionisation energies and atomisation energies of the alkali metals. Because the first ionisation energy of the alkali metals decreases down the group, it is easier for the outer... |
Alkali metal | Electronegativity | Electronegativity
thumb|upright=1.25|Periodic variation of Pauling electronegativities as one descends the main groups of the periodic table from the second to the sixth period.
Electronegativity is a chemical property that describes the tendency of an atom or a functional group to attract electrons (or electron den... |