Helium (He)
noble-gasGas
Nguyên tử khối chuẩn
4,002602 uCấu hình electron
1s2Nhiệt độ nóng chảy
-272,2 °CNhiệt độ sôi
-268,93 °CKhối lượng riêng
0,1785 kg/m³Trạng thái oxi hóa
0Độ âm điện (Pauling)
Không cóNăng lượng ion hóa (lần 1)
24,587389 eVNăm phát hiện
1868Bán kính nguyên tử
120 pmChi tiết
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
Hình ảnh
Tính chất
Vật lý
- Bán kính nguyên tử (thực nghiệm)
- 120 pm So sánh Bán kính nguyên tử (thực nghiệm) của tất cả nguyên tố →
- Bán kính cộng hóa trị
- 28 pm So sánh Bán kính cộng hóa trị của tất cả nguyên tố →
- Bán kính van der Waals
- 140 pm So sánh Bán kính van der Waals của tất cả nguyên tố →
- Khối lượng riêng
- 0,1785 kg/m³ So sánh Khối lượng riêng của tất cả nguyên tố →
- Thể tích mol
- 0,0318 L/mol
- Pha ở STP
- Khí So sánh Pha ở STP của tất cả nguyên tố →
- Nhiệt độ nóng chảy
- -272,2 °C So sánh Nhiệt độ nóng chảy của tất cả nguyên tố →
- Nhiệt độ sôi
- -268,93 °C So sánh Nhiệt độ sôi của tất cả nguyên tố →
- Độ dẫn nhiệt
- 0,152 W/(m·K) So sánh Độ dẫn nhiệt của tất cả nguyên tố →
- Nhiệt dung riêng
- 5,193 J/(g·K) So sánh Nhiệt dung riêng của tất cả nguyên tố →
- Nhiệt dung mol
- 20,786 J/(mol·K) So sánh Nhiệt dung mol của tất cả nguyên tố →
- Cấu trúc tinh thể
- Lục phương xếp chặt So sánh Cấu trúc tinh thể của tất cả nguyên tố →
Hóa học
- Độ âm điện (Allen)
- 4,16
- Ái lực electron
- -0,5 eV (giá trị âm — nguyên tử không được dự đoán liên kết thêm electron)
- Năng lượng ion hóa (lần 1)
- 24,587389 eV So sánh Năng lượng ion hóa (lần 1) của tất cả nguyên tố →
- Năng lượng ion hóa (lần 2)
- 54,417953 eV So sánh Năng lượng ion hóa (lần 2) của tất cả nguyên tố →
- Trạng thái oxi hóa
- 0 So sánh Trạng thái oxi hóa của tất cả nguyên tố →
- Electron hóa trị
- 2 So sánh Electron hóa trị của tất cả nguyên tố →
- Cấu hình electron
- 1s2
Nhiệt động lực học
- Điểm ba (nhiệt độ)
- -270,973 °C
- Điểm ba (áp suất)
- 5043 Pa
- Điểm tới hạn (nhiệt độ)
- -267,955 °C
- Điểm tới hạn (áp suất)
- 2,2746e+5 Pa
- Nhiệt nóng chảy
- 1,430274e-4 eV So sánh Nhiệt nóng chảy của tất cả nguyên tố →
- Nhiệt hóa hơi
- 8,291444e-4 eV So sánh Nhiệt hóa hơi của tất cả nguyên tố →
- Nhiệt nguyên tử hóa
- 0 eV
Hạt nhân
- Proton
- 2 So sánh Proton của tất cả nguyên tố →
- Neutron
- 2 So sánh Neutron của tất cả nguyên tố →
- Các đồng vị đã biết
- 8 So sánh Các đồng vị đã biết của tất cả nguyên tố →
- Đồng vị bền
- 2 So sánh Đồng vị bền của tất cả nguyên tố →
- Đồng vị bền nhất
- He-4
- Năm phát hiện
- 1868
Độ phổ biến
- Độ phổ biến (vỏ Trái Đất)
- 0,008 mg/kg So sánh Độ phổ biến (vỏ Trái Đất) của tất cả nguyên tố →
- Độ phổ biến (đại dương)
- 7 × 10−6 mg/L So sánh Độ phổ biến (đại dương) của tất cả nguyên tố →
Cấu trúc tinh thể
- Hằng số mạng a
- 357 pm
Cấu trúc electron
- Số electron trong mỗi lớp
- 2 So sánh Số electron trong mỗi lớp của tất cả nguyên tố →
Mã định danh
- Số CAS
- 7440-59-7 So sánh Số CAS của tất cả nguyên tố →
- Ký hiệu số hạng
- 1S0
- InChI
- InChI=1S/He
- Khóa InChI
- SWQJXJOGLNCZEY-UHFFFAOYSA-N
Cấu hình electron Đo đạc
He: 1s²1s²1s²Mô hình nguyên tử
Các đồng vị khác nhau về số neutron, khối lượng và độ bền — không khác nhau về cấu hình electron của nguyên tử trung hòa.
Mô hình nguyên tử minh họa, không theo tỷ lệ.
Dấu vân tay nguyên tử
Phổ phát xạ / hấp thụ
Phân bố đồng vị
| Số khối | Khối lượng nguyên tử (u) | Độ phổ biến tự nhiên | Chu kỳ bán rã |
|---|---|---|---|
| 3 Bền | 3,0160293201 ± 0,0000000025 | 0,0001% | Bền |
| 4 Bền | 4,00260325413 ± 0,00000000006 | 99,9999% | Bền |
Pha / Trạng thái
Lý do: cao hơn nhiệt độ sôi (-268,93 °C) một lượng 293,9 °C
Sơ đồ minh họa, không theo tỷ lệ
Điểm chuyển pha
Năng lượng chuyển pha
Năng lượng cần để làm nóng chảy 1 mol tại nhiệt độ nóng chảy
Năng lượng cần để hóa hơi 1 mol tại nhiệt độ sôi
Khối lượng riêng
Ở điều kiện chuẩn
Ước tính theo phương trình khí lý tưởng tại T hiện tại
Nâng cao
Phổ nguyên tử
Dữ liệu vạch phổ ?
| Ion | Điện tích | Tổng số vạch | Xác suất chuyển mức | Ký hiệu mức năng lượng |
|---|---|---|---|---|
| 3He I Đồng vị | 0 | 2289 | 0 | 2289 |
| He I | 0 | 2300 | 2289 | 2300 |
| He II | +1 | 140 | 140 | 140 |
| 3He II Đồng vị | +1 | 140 | 140 | 140 |
Dữ liệu mức năng lượng ?
| Ion | Điện tích | Mức năng lượng |
|---|---|---|
| 3He I Đồng vị | 0 | 188 |
| He I | 0 | 843 |
| He II | +1 | 149 |
| 3He II Đồng vị | +1 | 149 |
Hợp chất
Đồng vị (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.
| Số khối | Khối lượng nguyên tử (u) | Độ phổ biến tự nhiên | Chu kỳ bán rã | Kiểu phân rã | |
|---|---|---|---|---|---|
| 3 Bền | 3,0160293201 ± 0,0000000025 | 0,0001% ± 0,0000% | Bền | stable | |
| 4 Bền | 4,00260325413 ± 0,00000000006 | 99,9999% ± 0,0000% | Bền | stable |
Vạch phổ
| Bước sóng (nm) | Cường độ | Bậc ion hóa | Loại | Chuyển mức | Độ chính xác | Nguồn | |
|---|---|---|---|---|---|---|---|
| 381.9601975 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 381.9602773 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 381.9602828 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 381.9613129 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 381.9613927 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 381.975731 nm | 1 | He I | emission | 1s.2p 3P* → 1s.6d 3D | Đo đạc | NIST | |
| 383.3548713 nm | 0 | He I | emission | 1s.2p 1P* → 1s.10d 1D | Đo đạc | NIST | |
| 383.8100125 nm | Không có | He I | emission | 1s.2p 1P* → 1s.10s 1S | Đo đạc | NIST | |
| 386.7472343 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6s 3S | Đo đạc | NIST | |
| 386.7483778 nm | Không có | He I | emission | 1s.2p 3P* → 1s.6s 3S | Đo đạc | NIST | |
| 386.7631595 nm | 1 | He I | emission | 1s.2p 3P* → 1s.6s 3S | Đo đạc | NIST | |
| 387.1786406 nm | 1 | He I | emission | 1s.2p 1P* → 1s.9d 1D | Đo đạc | NIST | |
| 387.8176858 nm | Không có | He I | emission | 1s.2p 1P* → 1s.9s 1S | Đo đạc | NIST | |
| 388.8604644 nm | Không có | He I | emission | 1s.2s 3S → 1s.3p 3P* | Đo đạc | NIST | |
| 388.864559 nm | Không có | He I | emission | 1s.2s 3S → 1s.3p 3P* | Đo đạc | NIST | |
| 388.8648915 nm | Không có | He I | emission | 1s.2s 3S → 1s.3p 3P* | Đo đạc | NIST | |
| 392.6544387 nm | 1 | He I | emission | 1s.2p 1P* → 1s.8d 1D | Đo đạc | NIST | |
| 393.5945223 nm | 0 | He I | emission | 1s.2p 1P* → 1s.8s 1S | Đo đạc | NIST | |
| 396.4728829 nm | 20 | He I | emission | 1s.2s 1S → 1s.4p 1P* | Đo đạc | NIST | |
| 397.2015454 nm | Không có | He I | emission | 1s.2s 1S → 1s.4d 1D | Đo đạc | NIST | |
| 400.9256516 nm | 1 | He I | emission | 1s.2p 1P* → 1s.7d 1D | Đo đạc | NIST | |
| 402.3979795 nm | 1 | He I | emission | 1s.2p 1P* → 1s.7s 1S | Đo đạc | NIST | |
| 402.6184368 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 402.6185901 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 402.6186005 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 402.619676 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 402.6198294 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 402.6356959 nm | 5 | He I | emission | 1s.2p 3P* → 1s.5d 3D | Đo đạc | NIST | |
| 412.0810765 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5s 3S | Đo đạc | NIST | |
| 412.0823747 nm | Không có | He I | emission | 1s.2p 3P* → 1s.5s 3S | Đo đạc | NIST | |
| 412.0991564 nm | 2 | He I | emission | 1s.2p 3P* → 1s.5s 3S | Đo đạc | NIST | |
| 414.1332157 nm | Không có | He I | emission | 1s.2p 1P* → 1s.6p 1P* | Đo đạc | NIST | |
| 414.3759059 nm | 3 | He I | emission | 1s.2p 1P* → 1s.6d 1D | Đo đạc | NIST | |
| 416.8971512 nm | 1 | He I | emission | 1s.2p 1P* → 1s.6s 1S | Đo đạc | NIST | |
| 438.3278555 nm | Không có | He I | emission | 1s.2p 1P* → 1s.5p 1P* | Đo đạc | NIST | |
| 438.7929143 nm | 10 | He I | emission | 1s.2p 1P* → 1s.5d 1D | Đo đạc | NIST | |
| 443.7553428 nm | 3 | He I | emission | 1s.2p 1P* → 1s.5s 1S | Đo đạc | NIST | |
| 447.1470373 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 447.1474077 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 447.1474317 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 447.1485658 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 447.1489362 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 447.1683251 nm | 25 | He I | emission | 1s.2p 3P* → 1s.4d 3D | Đo đạc | NIST | |
| 468.537685 nm | Không có | He II | emission | 3p 2P* → 4d 2D | Đo đạc | NIST | |
| 468.5407226 nm | Không có | He II | emission | 3s 2S → 4p 2P* | Đo đạc | NIST | |
| 468.5524404 nm | Không có | He II | emission | 3p 2P* → 4s 2S | Đo đạc | NIST | |
| 468.5568006 nm | Không có | He II | emission | 3s 2S → 4p 2P* | Đo đạc | NIST | |
| 468.570385 nm | Không có | He II | emission | 3d 2D → 4f 2F* | Đo đạc | NIST | |
| 468.570438 nm | Không có | He II | emission | 3p 2P* → 4d 2D | Đo đạc | NIST | |
| 468.575708 nm | Không có | He II | emission | 3d 2D → 4p 2P* | Đo đạc | NIST | |
| 468.5757975 nm | Không có | He II | emission | 3p 2P* → 4d 2D | Đo đạc | NIST | |
| 468.5804092 nm | Không có | He II | emission | 3d 2D → 4f 2F* | Đo đạc | NIST | |
| 468.583089 nm | Không có | He II | emission | 3d 2D → 4f 2F* | Đo đạc | NIST | |
| 468.5884123 nm | Không có | He II | emission | 3d 2D → 4p 2P* | Đo đạc | NIST | |
| 468.5905553 nm | Không có | He II | emission | 3p 2P* → 4s 2S | Đo đạc | NIST | |
| 468.5917885 nm | Không có | He II | emission | 3d 2D → 4p 2P* | Đo đạc | NIST | |
| 471.3139173 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4s 3S | Đo đạc | NIST | |
| 471.3156155 nm | Không có | He I | emission | 1s.2p 3P* → 1s.4s 3S | Đo đạc | NIST | |
| 471.3375684 nm | 4 | He I | emission | 1s.2p 3P* → 1s.4s 3S | Đo đạc | NIST | |
| 491.074748 nm | Không có | He I | emission | 1s.2p 1P* → 1s.4p 1P* | Đo đạc | NIST | |
| 492.0612726 nm | Không có | He I | emission | 1s.2p 1P* → 1s.4f 1F* | Đo đạc | NIST | |
| 492.1931036 nm | 20 | He I | emission | 1s.2p 1P* → 1s.4d 1D | Đo đạc | NIST | |
| 501.567801 nm | 100 | He I | emission | 1s.2s 1S → 1s.3p 1P* | Đo đạc | NIST | |
| 504.208749 nm | Không có | He I | emission | 1s.2s 1S → 1s.3d 1D | Đo đạc | NIST | |
| 504.773857 nm | 10 | He I | emission | 1s.2p 1P* → 1s.4s 1S | Đo đạc | NIST | |
| 587.443388 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 1D | Đo đạc | NIST | |
| 587.446026 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 1D | Đo đạc | NIST | |
| 587.559871 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 587.561397 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 587.561484 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 587.56251 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 587.564036 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 587.596628 nm | 100 | He I | emission | 1s.2p 3P* → 1s.3d 3D | Đo đạc | NIST | |
| 655.976872 nm | Không có | He II | emission | 4p 2P* → 6d 2D | Đo đạc | NIST | |
| 655.979395 nm | Không có | He II | emission | 4s 2S → 6p 2P* | Đo đạc | NIST | |
| 655.98544 nm | Không có | He II | emission | 4p 2P* → 6s 2S | Đo đạc | NIST | |
| 655.988733 nm | Không có | He II | emission | 4s 2S → 6p 2P* | Đo đạc | NIST | |
| 656.005227 nm | Không có | He II | emission | 4d 2D → 6f 2F* | Đo đạc | NIST | |
| 656.005274 nm | Không có | He II | emission | 4p 2P* → 6d 2D | Đo đạc | NIST | |
| 656.008318 nm | Không có | He II | emission | 4d 2D → 6p 2P* | Đo đạc | NIST | |
| 656.008387 nm | Không có | He II | emission | 4p 2P* → 6d 2D | Đo đạc | NIST | |
| 656.01416 nm | Không có | He II | emission | 4f 2F* → 6g 2G | Đo đạc | NIST | |
| 656.014176 nm | Không có | He II | emission | 4d 2D → 6f 2F* | Đo đạc | NIST | |
| 656.015708 nm | Không có | He II | emission | 4f 2F* → 6d 2D | Đo đạc | NIST | |
| 656.015732 nm | Không có | He II | emission | 4d 2D → 6f 2F* | Đo đạc | NIST | |
| 656.016955 nm | Không có | He II | emission | 4p 2P* → 6s 2S | Đo đạc | NIST | |
| 656.017657 nm | Không có | He II | emission | 4d 2D → 6p 2P* | Đo đạc | NIST | |
| 656.018478 nm | Không có | He II | emission | 4f 2F* → 6g 2G | Đo đạc | NIST | |
| 656.01882 nm | Không có | He II | emission | 4f 2F* → 6d 2D | Đo đạc | NIST | |
| 656.018823 nm | Không có | He II | emission | 4d 2D → 6p 2P* | Đo đạc | NIST | |
| 656.019412 nm | Không có | He II | emission | 4f 2F* → 6g 2G | Đo đạc | NIST | |
| 656.02096 nm | Không có | He II | emission | 4f 2F* → 6d 2D | Đo đạc | NIST | |
| 663.190187 nm | Không có | He I | emission | 1s.2p 1P* → 1s.3p 1P* | Đo đạc | NIST | |
| 667.815174 nm | 100 | He I | emission | 1s.2p 1P* → 1s.3d 1D | Đo đạc | NIST | |
| 667.967687 nm | Không có | He I | emission | 1s.2p 1P* → 1s.3d 3D | Đo đạc | NIST | |
| 706.517716 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3s 3S | Đo đạc | NIST | |
| 706.521532 nm | Không có | He I | emission | 1s.2p 3P* → 1s.3s 3S | Đo đạc | NIST | |
| 706.570863 nm | 30 | He I | emission | 1s.2p 3P* → 1s.3s 3S | Đo đạc | NIST | |
| 716.055563 nm | Không có | He I | emission | 1s.3s 3S → 1s.10p 3P* | Đo đạc | NIST | |
| 716.055907 nm | Không có | He I | emission | 1s.3s 3S → 1s.10p 3P* | Đo đạc | NIST | |
| 716.055935 nm | Không có | He I | emission | 1s.3s 3S → 1s.10p 3P* | Đo đạc | NIST | |
| 728.13508 nm | 50 | He I | emission | 1s.2p 1P* → 1s.3s 1S | Đo đạc | NIST | |
| 729.803204 nm | Không có | He I | emission | 1s.3s 3S → 1s.9p 3P* | Đo đạc | NIST | |
| 729.803696 nm | Không có | He I | emission | 1s.3s 3S → 1s.9p 3P* | Đo đạc | NIST | |
| 729.803736 nm | Không có | He I | emission | 1s.3s 3S → 1s.9p 3P* | Đo đạc | NIST | |
| 749.984714 nm | Không có | He I | emission | 1s.3s 3S → 1s.8p 3P* | Đo đạc | NIST | |
| 749.985457 nm | Không có | He I | emission | 1s.3s 3S → 1s.8p 3P* | Đo đạc | NIST | |
| 749.985518 nm | Không có | He I | emission | 1s.3s 3S → 1s.8p 3P* | Đo đạc | NIST |
Tính chất mở rộng
Bán kính cộng hóa trị (mở rộng)
- Bán kính cộng hóa trị (Pyykkö)
- 46 pm
Bán kính van der Waals
- Bondi
- 140 pm
- Alvarez
- 143 pm
- UFF
- 236,2 pm
- MM3
- 153 pm
Bán kính nguyên tử và kim loại
- Bán kính nguyên tử (Rahm)
- 134 pm
- Bán kính kim loại (C12)
- 122 pm
Các thang đánh số
- Mendeleev
- 112
- Pettifor
- 1
- Glawe
- 1
Các thang độ âm điện
- Ghosh
- 0
- Gunnarsson–Lundqvist
- 8
- Robles–Bartolotti
- 8
Độ phân cực hóa và tán sắc
- Độ phân cực hóa lưỡng cực
- 1,3838 a.u.
- Độ phân cực hóa lưỡng cực (độ không đảm bảo)
- 0 a.u.
- C₆
- 1,42 Ha·Bohr6
- C₆ (Gould–Bučko)
- 1,47 Ha·Bohr6
Ái lực hóa học
- Ái lực proton
- 177,8 kJ/mol
- Độ bazơ pha khí
- 148,5 kJ/mol
Rủi ro nguồn cung và kinh tế
- Mức độ tập trung sản xuất
- 22
- Rủi ro nguồn cung tương đối
- 7
- Phân bố trữ lượng
- 21
- Ổn định chính trị (quốc gia sản xuất lớn nhất)
- 57
- Ổn định chính trị (quốc gia có trữ lượng lớn nhất)
- 57
Tính chất khí hiếm
Chuyển pha và các dạng thù hình
| Nhiệt độ sôi | 4,22 K |
| Điểm tới hạn (nhiệt độ) | 5,19 K |
| Điểm tới hạn (áp suất) | 0,23 MPa |
| Điểm ba (nhiệt độ) | 2,18 K |
| Điểm ba (áp suất) | 5,04 kPa |
Dữ liệu tham khảo chuyên sâu
Hằng số chắn (1)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 0,3125 |
Các kiểu phân rã đồng vị (9)
| Đồng vị | Chế độ | Cường độ |
|---|---|---|
| 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% |
Hệ số tán xạ tia X (501)
| Năng lượng (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 |
Dữ liệu bổ sung
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
8×10-3 milligrams per kilogram
Tài liệu tham khảo (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7×10-6 milligrams per liter
Tài liệu tham khảo (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.
Tài liệu tham khảo (1)
- [6] Helium https://periodic.lanl.gov/2.shtml
Tài liệu tham khảo
(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.