Helium (He)
noble-gasGas
표준 원자량
4.002602 u전자 배치
1s2녹는점
-272.2 °C끓는점
-268.93 °C밀도
0.1785 kg/m³산화 상태
0전기 음성도(Pauling)
해당 없음제1 이온화 에너지
24.587389 eV발견 연도
1868원자 반지름
120 pm상세 정보
Helium is a noble gas and the second element in the periodic table. It is chemically inert under ordinary conditions because its 1s electron shell is filled, and it exists as monatomic He rather than as a molecule. Its low density, very low boiling point, high thermal conductivity, and nonflammability make it technologically important. On Earth it is uncommon in the atmosphere but can accumulate in some natural gas reservoirs through radioactive decay of uranium and thorium.
Helium has the lowest melting point of any element and is widely used in cryogenic research because its boiling point is close to absolute zero. Also, the element is vital in the study of super conductivity.
Using liquid helium, Kurti, co-workers and others have succeeded in obtaining temperatures of a few microkelvins by the adiabatic demagnetization of copper nuclei.
Helium has other peculiar properties: It is the only liquid that cannot be solidified by lowering the temperature. It remains liquid down to absolute zero at ordinary pressures, but will readily solidify by increasing the pressure. Solid 3He and 4He are unusual in that both can be changed in volume by more than 30% by applying pressure.
The specific heat of helium gas is unusually high. The density of helium vapor at the normal boiling point is also very high, with the vapor expanding greatly when heated to room temperature. Containers filled with helium gas at 5 to 10 K should be treated as though they contained liquid helium due to the large increase in pressure resulting from warming the gas to room temperature.
While helium normally has a 0 valence, it seems to have a weak tendency to combine with certain other elements. Means of preparing helium difluoride have been studied, and species such as HeNe and the molecular ions He+ and He++ have been investigated.
The name derives from the Greek helios for "sun". The element was discovered by spectroscopy during a solar eclipse in the sun's chromosphere by the French astronomer Pierre-Jules-Cesar Janssen in 1868. It was independently discovered and named helium by the English astronomer Joseph Norman Lockyer.
Helium was thought to be only a solar constituent until it was later found to be identical to the helium in the uranium ore cleveite by the Scottish chemist William Ramsay in 1895. The Swedish chemists Per Theodore Cleve and Nils Abraham Langet independently found helium in cleveite at about the same time.
Helium, the second most abundant element in the universe, was discovered on the sun before it was found on the earth. Pierre-Jules-César Janssen, a French astronomer, noticed a yellow line in the sun's spectrum while studying a total solar eclipse in 1868. Sir Norman Lockyer, an English astronomer, realized that this line, with a wavelength of 587.49 nanometers, could not be produced by any element known at the time. It was hypothesized that a new element on the sun was responsible for this mysterious yellow emission. This unknown element was named helium by Lockyer. The hunt to find helium on earth ended in 1895. Sir William Ramsay, a Scottish chemist, conducted an experiment with a mineral containing uranium called clevite. He exposed the clevite to mineral acids and collected the gases that were produced. He then sent a sample of these gases to two scientists, Lockyer and Sir William Crookes, who were able to identify the helium within it. Two Swedish chemists, Nils Langlet and Per Theodor Cleve, independently found helium in clevite at about the same time as Ramsay.
Helium makes up about 0.0005% of the earth's atmosphere. This trace amount of helium is not gravitationally bound to the earth and is constantly lost to space. The earth's atmospheric helium is replaced by the decay of radioactive elements in the earth's crust. Alpha decay, one type of radioactive decay, produces particles called alpha particles. An alpha particle can become a helium atom once it captures two electrons from its surroundings. This newly formed helium can eventually work its way to the atmosphere through cracks in the crust.
From the Greek word helios, the sun. Janssen obtained the first evidence of helium during the solar eclipse of 1868 when he detected a new line in the solar spectrum. Lockyer and Frankland suggested the name helium for the new element. In 1895 Ramsay discovered helium in the uranium mineral cleveite while it was independently discovered in cleveite by the Swedish chemists Cleve and Langlet at about the same time. Rutherford and Royds in 1907 demonstrated that alpha particles are helium nuclei.
Pure helium is a colorless, odorless, tasteless gas at ordinary temperature and pressure. It liquefies only at very low temperature and does not freeze at normal pressure, remaining liquid down to absolute zero unless compressed. Liquid helium is clear and highly mobile.
Helium is used where an inert, light, and very cold fluid is needed. Liquid helium cools superconducting magnets in magnetic resonance imaging, particle accelerators, and low-temperature research. Gaseous helium is used as a shielding gas in specialized welding, as a leak-detection tracer, as a pressurizing and purging gas for rockets and cryogenic systems, and as a carrier gas in gas chromatography. Helium also fills balloons and airships when nonflammability is more important than lift efficiency. Helium-3 is used in neutron detection, cryogenic research, and some specialized physics experiments, but its supply is limited.
Helium is commercially recovered from natural gas deposits, mostly from Texas, Oklahoma and Kansas. Helium gas is used to inflate blimps, scientific balloons and party balloons. It is used as an inert shield for arc welding, to pressurize the fuel tanks of liquid fueled rockets and in supersonic windtunnels. Helium is combined with oxygen to create a nitrogen free atmosphere for deep sea divers so that they will not suffer from a condition known as nitrogen narcosis. Liquid helium is an important cryogenic material and is used to study superconductivity and to create superconductive magnets. The Department of Energy's Jefferson Lab uses large amounts of liquid helium to operate its superconductive electron accelerator.
Helium is an inert gas and does not easily combine with other elements. There are no known compounds that contain helium, although attempts are being made to produce helium diflouride (HeF2).
▸ as an inert gas shield for arc welding;
▸ a protective gas in growing silicon and germanium crystals and producing titanium and zirconium;
▸ as a cooling medium for nuclear reactors, and
▸ as a gas for supersonic wind tunnels.
A mixture of helium and oxygen is used as an artificial atmosphere for divers and others working under pressure. Different ratios of He and O2 are used for different diver operation depths.
Helium is extensively used for filling balloons as it is a much safer gas than hydrogen. One of the recent largest uses for helium has been for pressuring liquid fuel rockets. A Saturn booster, like the type used on the Apollo lunar missions, required about 13 million ft3 of helium for a firing, plus more for checkouts.
Liquid helium's use in magnetic resonance imaging (MRI) continues to increase as the medical profession accepts and develops new uses for the equipment. This equipment has eliminated some need for exploratory surgery by accurately diagnosing patients. Another medical application uses MRE to determine (by blood analysis) whether a patient has any form of cancer.
Helium is also being used to advertise on blimps for various companies, including Goodyear. Other lifting gas applications are being developed by the Navy and Air Force to detect low-flying cruise missiles. Additionally, the Drug Enforcement Agency is using radar-equipped blimps to detect drug smugglers along the United States boarders. In addition, NASA is currently using helium-filled balloons to sample the atmosphere in Antarctica to determine what is depleting the ozone layer.
Isotopes in Geochronology
3He is a product of the radioactive decay of 3H (half-life of 12.31 years). The relative variations in the amount ratio n(3He)/n(3H) can be interpreted in terms of elapsed time. This has been especially useful in aquatic systems, including oceans, lakes, and aquifers, that received large inputs of 3H from precipitation following thermonuclear bomb test periods. 3H- 3He dating provides the elapsed time since a water mass became isolated from the atmosphere in the time range from the mid-1950s to the present. Such studies are important for establishing the sustainability of groundwater resources in shallow aquifers [27] D. K. Solomon, P. G. Cook. “3H and 3He”, in Environmental Tracers in Subsurface Hydrology, P. G. Cook and A. L. Herczeg (Eds.), Kluwer Academic Publishers, Boston (2000)., [28] P. Schlosser, M. Stute, H. Dörr, C. Sonntag, K. O. Münnich. Earth Planet. Sci. Lett.89, 353 (1988)..
4He is a product of radioactive decay in the uranium and thorium decay series. As a result, 4He concentration is used to estimate the relative ages of minerals and groundwater. In closed systems (systems that do not exchange matter with their surroundings), relative variations in the amount ratio n(4He)/n(U) can be interpreted in terms of elapsed time, although other processes can alter the distribution of helium, which is highly mobile in terrestrial environments [29] M. Ozima, F. A. Podosek. Noble Gas Geochemistry: 2nd Edition, p. 286, Cambridge University Press, Cambridge, UK (2002)., [30] D. K. Solomon. “4He in groundwater”, in Environmental Tracers in Subsurface Hydrology, P. G. Cook and A. L. Herczeg (Eds.), Kluwer Academic Publishers, Boston (2000)..
4He concentrations commonly increase along groundwater flow paths through a cumulative release from aquifer materials. This rate of accumulation is used to estimate the time since the groundwater was recharged at the surface. The 4He accumulation method of groundwater dating is typically used in deeper aquifers, where groundwater is relatively old and the 3H- 3He method cannot be used because of the relatively short half-life of 12.31 years for 3H [30] D. K. Solomon. “4He in groundwater”, in Environmental Tracers in Subsurface Hydrology, P. G. Cook and A. L. Herczeg (Eds.), Kluwer Academic Publishers, Boston (2000)..
Isotopes in Industry
3He has a large absorption cross section for neutrons, which makes it especially useful for radioactivity detection [31] D. Kramer. Phys. Today63, 22 (2010)., [32] G. V. Jean. Advancing Hidden Nuclear Material Detection, National Defense Industrial Association (2014), Feb. 28; http://www.nationaldefensemagazine.org/archive/2010/December/Pages/AdvancingHiddenNuclearMaterialDetection.aspx.. In this application, neutrons produced by the radioactive decay of elements, such as uranium and plutonium, enter the detector, where the reaction 3He (n, p) 3H produces 1H and 3H atoms. This induces further collisions and the release of electrons, which interact with charged surfaces to generate an electric current. Large amounts of 3He are used to produce neutron detectors in portal monitors for detecting illicit radioactive materials at ports, border crossings, and airports (Fig. IUPAC.2.1). Unfortunately, the isotope 3He is rare and there is a need to incorporate alternative gases for use in neutron detectors. 3He neutron detectors are also used in devices that determine the proportions of water, oil, and gas in wells drilled for energy production. Other important uses of 3He include lasers, gyroscopes used for missile stability and guidance, and cryogenic research (ultra-low temperature, less than 1 K).
The global supply of 3He available for research and practical applications has become severely limited in recent years, such that prices have increased substantially and some uses have been curtailed [31] D. Kramer. Phys. Today63, 22 (2010)., [32] G. V. Jean. Advancing Hidden Nuclear Material Detection, National Defense Industrial Association (2014), Feb. 28; http://www.nationaldefensemagazine.org/archive/2010/December/Pages/AdvancingHiddenNuclearMaterialDetection.aspx.. A major source of 3He is from nuclear weapons containing 3H, recovered when the warheads are reconditioned or dismantled. 3He accumulates in such devices as a radiogenic product of 3H decay. The annual supply of new 3He has decreased with reductions in nuclear arsenals.
Isotopes in Medicine
3He is used as an inhalant to improve magnetic resonance imaging (MRI) of the lungs [34] M. Ebert, T. Grossmann, W. Heil, E. W. Otten, R. Surkau, M. Thelen, M. Leduc, P. Bachert, M. V. Knopp, L. R. Schad. Lancet347, 1297 (1996)..
Helium has no stable neutral compounds under ordinary chemical conditions. Its closed-shell atom has an extremely high ionization energy and very low polarizability, so conventional covalent or ionic chemistry is absent. Excited helium can form transient species such as the helium dimer ion He₂⁺ and excimers in plasmas. Under high pressure, helium can enter crystalline inclusion compounds and van der Waals solids; sodium helide, often written Na₂He, has been reported as a high-pressure electride rather than a normal valence compound. These phases are not examples of everyday helium chemistry.
See more information at the Helium compound page.
Helium is not toxic and is not flammable, but it can displace oxygen in confined spaces and cause asphyxiation without warning. Compressed helium cylinders present mechanical hazards if mishandled. Liquid helium can cause severe cold burns and can rapidly expand to large gas volumes, creating pressure and oxygen-deficiency risks. Inhalation to alter the voice is dangerous because it can deprive the body of oxygen or cause pressure injury from cylinders.
Most terrestrial helium is produced by alpha decay in rocks; alpha particles become helium nuclei and then neutral atoms. Because helium is light and unreactive, it migrates through rocks, dissolves only weakly in water, and eventually escapes from the atmosphere to space. Commercially recoverable accumulations require suitable source rocks and trapping structures, often associated with natural gas fields. Helium has no known biological requirement and little direct chemical ecological effect.
Helium is recovered chiefly as a by-product from natural gas streams that contain unusually high helium concentrations. Separation commonly uses cryogenic processing, pressure-swing adsorption, or membrane methods after removal of major gases. Supply is constrained by geology, gas-field development, purification capacity, storage, and transport of either compressed gas or cryogenic liquid. Demand is led by cryogenics, especially superconducting magnets, with additional use in leak detection, analytical instrumentation, welding, and aerospace systems. Recycling is technically valuable in laboratories and large facilities but is not universal, because capture and reliquefaction require specialized equipment.
Except for hydrogen, helium is the most abundant element found in the universe. Helium is extracted from natural gas. In fact, all natural gas contains at least trace quantities of helium.
It has been detected spectroscopically in great abundance, especially in the hotter stars, and it is an important component in both the proton-proton reaction and the carbon cycle, which account for the energy of the sun and stars.
The helium content of the atmosphere is about 1 part in 200,000. While it is present in various radioactive minerals as a decay product, the bulk of the Free World's supply is obtained from wells in Texas, Oklahoma, and Kansas. Outside the United States, the only known helium extraction plants, in 1984 were in Eastern Europe (Poland), the USSR, and a few in India.
Helium is one of the most abundant elements in the universe. Most ⁴He was formed during Big Bang nucleosynthesis, and more is produced by hydrogen fusion in stars. It is a major constituent of the Sun and gas giant planets. On rocky planets, atmospheric helium is usually depleted because neutral helium can escape gravitationally over geologic time.
- Helium was first identified in the solar spectrum before it was isolated on Earth.
- At normal pressure, helium is the only element that does not solidify by cooling alone.
- Liquid ⁴He becomes a superfluid below the lambda point near 2.17 K.
- Helium has a negative Joule-Thomson coefficient above its inversion temperature, so it can warm during throttling at the
이미지
특성
물리적 특성
- 원자 반지름(경험값)
- 120 pm 모든 원소의 원자 반지름(경험값) 비교 →
- 공유 결합 반지름
- 28 pm 모든 원소의 공유 결합 반지름 비교 →
- 반데르발스 반지름
- 140 pm 모든 원소의 반데르발스 반지름 비교 →
- 밀도
- 0.1785 kg/m³ 모든 원소의 밀도 비교 →
- 몰 부피
- 0.0318 L/mol
- STP에서의 상
- 기체 모든 원소의 STP에서의 상 비교 →
- 녹는점
- -272.2 °C 모든 원소의 녹는점 비교 →
- 끓는점
- -268.93 °C 모든 원소의 끓는점 비교 →
- 열전도율
- 0.152 W/(m·K) 모든 원소의 열전도율 비교 →
- 비열
- 5.193 J/(g·K) 모든 원소의 비열 비교 →
- 몰 열용량
- 20.786 J/(mol·K) 모든 원소의 몰 열용량 비교 →
- 결정 구조
- 육방 조밀 충전 모든 원소의 결정 구조 비교 →
화학적 특성
- 전기 음성도(Allen)
- 4.16
- 전자 친화도
- -0.5 eV (음수 값 — 추가 전자를 결합하지 않을 것으로 예측됨)
- 제1 이온화 에너지
- 24.587389 eV 모든 원소의 제1 이온화 에너지 비교 →
- 제2 이온화 에너지
- 54.417953 eV 모든 원소의 제2 이온화 에너지 비교 →
- 산화 상태
- 0 모든 원소의 산화 상태 비교 →
- 원자가 전자
- 2 모든 원소의 원자가 전자 비교 →
- 전자 배치
- 1s2
열역학적 특성
- 삼중점(온도)
- -270.973 °C
- 삼중점(압력)
- 5043 Pa
- 임계점(온도)
- -267.955 °C
- 임계점(압력)
- 2.2746e+5 Pa
- 융해열
- 1.430274e-4 eV 모든 원소의 융해열 비교 →
- 기화열
- 8.291444e-4 eV 모든 원소의 기화열 비교 →
- 원자화열
- 0 eV
핵 특성
- 양성자 수
- 2 모든 원소의 양성자 수 비교 →
- 중성자 수
- 2 모든 원소의 중성자 수 비교 →
- 알려진 동위원소 수
- 8 모든 원소의 알려진 동위원소 수 비교 →
- 안정 동위원소 수
- 2 모든 원소의 안정 동위원소 수 비교 →
- 가장 안정한 동위원소
- He-4
- 발견 연도
- 1868
존재비
- 존재비(지각)
- 0.008 mg/kg 모든 원소의 존재비(지각) 비교 →
- 존재비(해양)
- 7 × 10−6 mg/L 모든 원소의 존재비(해양) 비교 →
결정 구조
- 격자 상수 a
- 357 pm
전자 구조
- 전자껍질별 전자 수
- 2 모든 원소의 전자껍질별 전자 수 비교 →
식별자
- CAS 등록 번호
- 7440-59-7 모든 원소의 CAS 등록 번호 비교 →
- 항 기호
- 1S0
- InChI
- InChI=1S/He
- InChI 키
- SWQJXJOGLNCZEY-UHFFFAOYSA-N
전자 배치 측정값
He: 1s²1s²1s²원자 모형
동위원소에 따라 중성자 수, 질량, 안정성은 달라지지만, 중성 원자의 전자 배치는 달라지지 않습니다.
개략적인 원자 모형이며 실제 비율과 다릅니다.
원자 지문
방출 / 흡수 스펙트럼
동위원소 분포
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 |
|---|---|---|---|
| 3 안정 | 3.0160293201 ± 0.0000000025 | 0.0001% | 안정 |
| 4 안정 | 4.00260325413 ± 0.00000000006 | 99.9999% | 안정 |
상 / 상태
이유: 끓는점(-268.93 °C)보다 293.9 °C 높음
개략도이며 실제 비율과 다름
상전이점
전이 에너지
녹는점에서 1 mol을 녹이는 데 필요한 에너지
끓는점에서 1 mol을 기화시키는 데 필요한 에너지
밀도
표준 조건에서
현재 온도 T에서 이상 기체 법칙으로 추정
심화
원자 스펙트럼
보유 스펙트럼선 데이터 ?
| 이온 | 전하 | 총 스펙트럼선 수 | 전이 확률 | 준위 표기 |
|---|---|---|---|---|
| 3He I 동위원소 | 0 | 2289 | 0 | 2289 |
| He I | 0 | 2300 | 2289 | 2300 |
| He II | +1 | 140 | 140 | 140 |
| 3He II 동위원소 | +1 | 140 | 140 | 140 |
화합물
동위원소 (2)
Seven isotopes of helium are known: Liquid helium (He-4) exists in two forms: He-4I and He-4II, with a sharp transition point at 2.174K. He-4I (above this temperature) is a normal liquid, but He-4II (below it) is unlike any other known substance. It expands on cooling, its conductivity for heat is enormous, and neither its heat conduction nor viscosity obeys normal rules.
| 질량수 | 원자 질량(u) | 천연 존재비 | 반감기 | 붕괴 방식 | |
|---|---|---|---|---|---|
| 3 안정 | 3.0160293201 ± 0.0000000025 | 0.0001% ± 0.0000% | 안정 | stable | |
| 4 안정 | 4.00260325413 ± 0.00000000006 | 99.9999% ± 0.0000% | 안정 | stable |
스펙트럼선
| 파장(nm) | 세기 | 이온화 단계 | 유형 | 전이 | 정확도 | 출처 | |
|---|---|---|---|---|---|---|---|
| 381.9601975 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 381.9602773 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 381.9602828 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 381.9613129 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 381.9613927 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 381.975731 nm | 1 | He I | emission | 1s.2p 3P* → 1s.6d 3D | 측정값 | NIST | |
| 383.3548713 nm | 0 | He I | emission | 1s.2p 1P* → 1s.10d 1D | 측정값 | NIST | |
| 383.8100125 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.10s 1S | 측정값 | NIST | |
| 386.7472343 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6s 3S | 측정값 | NIST | |
| 386.7483778 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.6s 3S | 측정값 | NIST | |
| 386.7631595 nm | 1 | He I | emission | 1s.2p 3P* → 1s.6s 3S | 측정값 | NIST | |
| 387.1786406 nm | 1 | He I | emission | 1s.2p 1P* → 1s.9d 1D | 측정값 | NIST | |
| 387.8176858 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.9s 1S | 측정값 | NIST | |
| 388.8604644 nm | 해당 없음 | He I | emission | 1s.2s 3S → 1s.3p 3P* | 측정값 | NIST | |
| 388.864559 nm | 해당 없음 | He I | emission | 1s.2s 3S → 1s.3p 3P* | 측정값 | NIST | |
| 388.8648915 nm | 해당 없음 | He I | emission | 1s.2s 3S → 1s.3p 3P* | 측정값 | NIST | |
| 392.6544387 nm | 1 | He I | emission | 1s.2p 1P* → 1s.8d 1D | 측정값 | NIST | |
| 393.5945223 nm | 0 | He I | emission | 1s.2p 1P* → 1s.8s 1S | 측정값 | NIST | |
| 396.4728829 nm | 20 | He I | emission | 1s.2s 1S → 1s.4p 1P* | 측정값 | NIST | |
| 397.2015454 nm | 해당 없음 | He I | emission | 1s.2s 1S → 1s.4d 1D | 측정값 | NIST | |
| 400.9256516 nm | 1 | He I | emission | 1s.2p 1P* → 1s.7d 1D | 측정값 | NIST | |
| 402.3979795 nm | 1 | He I | emission | 1s.2p 1P* → 1s.7s 1S | 측정값 | NIST | |
| 402.6184368 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 402.6185901 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 402.6186005 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 402.619676 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 402.6198294 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 402.6356959 nm | 5 | He I | emission | 1s.2p 3P* → 1s.5d 3D | 측정값 | NIST | |
| 412.0810765 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5s 3S | 측정값 | NIST | |
| 412.0823747 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.5s 3S | 측정값 | NIST | |
| 412.0991564 nm | 2 | He I | emission | 1s.2p 3P* → 1s.5s 3S | 측정값 | NIST | |
| 414.1332157 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.6p 1P* | 측정값 | NIST | |
| 414.3759059 nm | 3 | He I | emission | 1s.2p 1P* → 1s.6d 1D | 측정값 | NIST | |
| 416.8971512 nm | 1 | He I | emission | 1s.2p 1P* → 1s.6s 1S | 측정값 | NIST | |
| 438.3278555 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.5p 1P* | 측정값 | NIST | |
| 438.7929143 nm | 10 | He I | emission | 1s.2p 1P* → 1s.5d 1D | 측정값 | NIST | |
| 443.7553428 nm | 3 | He I | emission | 1s.2p 1P* → 1s.5s 1S | 측정값 | NIST | |
| 447.1470373 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 447.1474077 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 447.1474317 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 447.1485658 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 447.1489362 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 447.1683251 nm | 25 | He I | emission | 1s.2p 3P* → 1s.4d 3D | 측정값 | NIST | |
| 468.537685 nm | 해당 없음 | He II | emission | 3p 2P* → 4d 2D | 측정값 | NIST | |
| 468.5407226 nm | 해당 없음 | He II | emission | 3s 2S → 4p 2P* | 측정값 | NIST | |
| 468.5524404 nm | 해당 없음 | He II | emission | 3p 2P* → 4s 2S | 측정값 | NIST | |
| 468.5568006 nm | 해당 없음 | He II | emission | 3s 2S → 4p 2P* | 측정값 | NIST | |
| 468.570385 nm | 해당 없음 | He II | emission | 3d 2D → 4f 2F* | 측정값 | NIST | |
| 468.570438 nm | 해당 없음 | He II | emission | 3p 2P* → 4d 2D | 측정값 | NIST | |
| 468.575708 nm | 해당 없음 | He II | emission | 3d 2D → 4p 2P* | 측정값 | NIST | |
| 468.5757975 nm | 해당 없음 | He II | emission | 3p 2P* → 4d 2D | 측정값 | NIST | |
| 468.5804092 nm | 해당 없음 | He II | emission | 3d 2D → 4f 2F* | 측정값 | NIST | |
| 468.583089 nm | 해당 없음 | He II | emission | 3d 2D → 4f 2F* | 측정값 | NIST | |
| 468.5884123 nm | 해당 없음 | He II | emission | 3d 2D → 4p 2P* | 측정값 | NIST | |
| 468.5905553 nm | 해당 없음 | He II | emission | 3p 2P* → 4s 2S | 측정값 | NIST | |
| 468.5917885 nm | 해당 없음 | He II | emission | 3d 2D → 4p 2P* | 측정값 | NIST | |
| 471.3139173 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4s 3S | 측정값 | NIST | |
| 471.3156155 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.4s 3S | 측정값 | NIST | |
| 471.3375684 nm | 4 | He I | emission | 1s.2p 3P* → 1s.4s 3S | 측정값 | NIST | |
| 491.074748 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.4p 1P* | 측정값 | NIST | |
| 492.0612726 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.4f 1F* | 측정값 | NIST | |
| 492.1931036 nm | 20 | He I | emission | 1s.2p 1P* → 1s.4d 1D | 측정값 | NIST | |
| 501.567801 nm | 100 | He I | emission | 1s.2s 1S → 1s.3p 1P* | 측정값 | NIST | |
| 504.208749 nm | 해당 없음 | He I | emission | 1s.2s 1S → 1s.3d 1D | 측정값 | NIST | |
| 504.773857 nm | 10 | He I | emission | 1s.2p 1P* → 1s.4s 1S | 측정값 | NIST | |
| 587.443388 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 1D | 측정값 | NIST | |
| 587.446026 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 1D | 측정값 | NIST | |
| 587.559871 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 587.561397 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 587.561484 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 587.56251 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 587.564036 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 587.596628 nm | 100 | He I | emission | 1s.2p 3P* → 1s.3d 3D | 측정값 | NIST | |
| 655.976872 nm | 해당 없음 | He II | emission | 4p 2P* → 6d 2D | 측정값 | NIST | |
| 655.979395 nm | 해당 없음 | He II | emission | 4s 2S → 6p 2P* | 측정값 | NIST | |
| 655.98544 nm | 해당 없음 | He II | emission | 4p 2P* → 6s 2S | 측정값 | NIST | |
| 655.988733 nm | 해당 없음 | He II | emission | 4s 2S → 6p 2P* | 측정값 | NIST | |
| 656.005227 nm | 해당 없음 | He II | emission | 4d 2D → 6f 2F* | 측정값 | NIST | |
| 656.005274 nm | 해당 없음 | He II | emission | 4p 2P* → 6d 2D | 측정값 | NIST | |
| 656.008318 nm | 해당 없음 | He II | emission | 4d 2D → 6p 2P* | 측정값 | NIST | |
| 656.008387 nm | 해당 없음 | He II | emission | 4p 2P* → 6d 2D | 측정값 | NIST | |
| 656.01416 nm | 해당 없음 | He II | emission | 4f 2F* → 6g 2G | 측정값 | NIST | |
| 656.014176 nm | 해당 없음 | He II | emission | 4d 2D → 6f 2F* | 측정값 | NIST | |
| 656.015708 nm | 해당 없음 | He II | emission | 4f 2F* → 6d 2D | 측정값 | NIST | |
| 656.015732 nm | 해당 없음 | He II | emission | 4d 2D → 6f 2F* | 측정값 | NIST | |
| 656.016955 nm | 해당 없음 | He II | emission | 4p 2P* → 6s 2S | 측정값 | NIST | |
| 656.017657 nm | 해당 없음 | He II | emission | 4d 2D → 6p 2P* | 측정값 | NIST | |
| 656.018478 nm | 해당 없음 | He II | emission | 4f 2F* → 6g 2G | 측정값 | NIST | |
| 656.01882 nm | 해당 없음 | He II | emission | 4f 2F* → 6d 2D | 측정값 | NIST | |
| 656.018823 nm | 해당 없음 | He II | emission | 4d 2D → 6p 2P* | 측정값 | NIST | |
| 656.019412 nm | 해당 없음 | He II | emission | 4f 2F* → 6g 2G | 측정값 | NIST | |
| 656.02096 nm | 해당 없음 | He II | emission | 4f 2F* → 6d 2D | 측정값 | NIST | |
| 663.190187 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.3p 1P* | 측정값 | NIST | |
| 667.815174 nm | 100 | He I | emission | 1s.2p 1P* → 1s.3d 1D | 측정값 | NIST | |
| 667.967687 nm | 해당 없음 | He I | emission | 1s.2p 1P* → 1s.3d 3D | 측정값 | NIST | |
| 706.517716 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3s 3S | 측정값 | NIST | |
| 706.521532 nm | 해당 없음 | He I | emission | 1s.2p 3P* → 1s.3s 3S | 측정값 | NIST | |
| 706.570863 nm | 30 | He I | emission | 1s.2p 3P* → 1s.3s 3S | 측정값 | NIST | |
| 716.055563 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.10p 3P* | 측정값 | NIST | |
| 716.055907 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.10p 3P* | 측정값 | NIST | |
| 716.055935 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.10p 3P* | 측정값 | NIST | |
| 728.13508 nm | 50 | He I | emission | 1s.2p 1P* → 1s.3s 1S | 측정값 | NIST | |
| 729.803204 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.9p 3P* | 측정값 | NIST | |
| 729.803696 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.9p 3P* | 측정값 | NIST | |
| 729.803736 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.9p 3P* | 측정값 | NIST | |
| 749.984714 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.8p 3P* | 측정값 | NIST | |
| 749.985457 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.8p 3P* | 측정값 | NIST | |
| 749.985518 nm | 해당 없음 | He I | emission | 1s.3s 3S → 1s.8p 3P* | 측정값 | NIST |
확장 특성
공유 결합 반지름(확장)
- 공유 결합 반지름(Pyykkö)
- 46 pm
반데르발스 반지름
- Bondi
- 140 pm
- Alvarez
- 143 pm
- UFF
- 236.2 pm
- MM3
- 153 pm
원자 및 금속 반지름
- 원자 반지름(Rahm)
- 134 pm
- 금속 반지름(C12)
- 122 pm
번호 척도
- Mendeleev
- 112
- Pettifor
- 1
- Glawe
- 1
전기 음성도 척도
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 8
- Robles–Bartolotti
- 8
분극률 및 분산
- 쌍극자 분극률
- 1.3838 a.u.
- 쌍극자 분극률(불확도)
- 0 a.u.
- C₆
- 1.42 Ha·Bohr6
- C₆ (Gould–Bučko)
- 1.47 Ha·Bohr6
화학 친화력
- 양성자 친화도
- 177.8 kJ/mol
- 기체상 염기성
- 148.5 kJ/mol
공급 위험 및 경제성
- 생산 집중도
- 22
- 상대적 공급 위험
- 7
- 매장량 분포
- 21
- 정치적 안정성(최대 생산국)
- 57
- 정치적 안정성(최대 매장국)
- 57
비활성 기체 특성
상전이 및 동소체
| 끓는점 | 4.22 K |
| 임계점(온도) | 5.19 K |
| 임계점(압력) | 0.23 MPa |
| 삼중점(온도) | 2.18 K |
| 삼중점(압력) | 5.04 kPa |
심화 참고 데이터
차폐 상수 (1)
| n | 오비탈 | σ |
|---|---|---|
| 1 | s | 0.3125 |
동위원소 붕괴 방식 (9)
| 동위원소 | 모드 | 세기 |
|---|---|---|
| 5 | n | 100% |
| 6 | B- | 100% |
| 6 | B-d | 0% |
| 7 | n | 100% |
| 8 | B- | 100% |
| 8 | B-n | 16% |
| 8 | B-t | 0.9% |
| 9 | n | 100% |
| 10 | 2n | 100% |
X선 산란 인자 (501)
| 에너지 (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0 |
| 10.1617 | — | 0 |
| 10.3261 | — | 0 |
| 10.4931 | — | 0 |
| 10.6628 | — | 0 |
| 10.8353 | — | 0 |
| 11.0106 | — | 0 |
| 11.1886 | — | 0 |
| 11.3696 | — | 0 |
| 11.5535 | — | 0 |
추가 데이터
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
8×10-3 milligrams per kilogram
참고 문헌 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7×10-6 milligrams per liter
참고 문헌 (1)
Sources
Sources of this element.
Except for hydrogen, helium is the most abundant element found in the universe. Helium is extracted from natural gas. In fact, all natural gas contains at least trace quantities of helium.
It has been detected spectroscopically in great abundance, especially in the hotter stars, and it is an important component in both the proton-proton reaction and the carbon cycle, which account for the energy of the sun and stars.
The helium content of the atmosphere is about 1 part in 200,000. While it is present in various radioactive minerals as a decay product, the bulk of the Free World's supply is obtained from wells in Texas, Oklahoma, and Kansas. Outside the United States, the only known helium extraction plants, in 1984 were in Eastern Europe (Poland), the USSR, and a few in India.
참고 문헌 (1)
- [6] Helium https://periodic.lanl.gov/2.shtml
참고 문헌
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Helium.
The element property data was retrieved from publications.