Litium-7 (⁷Li)

Data nuklida

Unsur

Litium (Li, Z = 3)

Nomor massa (A)

7

Proton (Z)

3

Neutron (N)

4

Massa atom

7.01600343426 ± 0.0000000045 u

Waktu paruh

Stabil

Mode peluruhan

Tidak meluruh

Kelimpahan alami

[0.922, 0.981]

Tahun penemuan

1921

Sumber data

IAEA Atomic Mass Data Center (NUBASE) and IUPAC CIAAW, via PubChem

Kegunaan isotop litium

• Because molecules, atoms, and ions of the stable isotopes of lithium possess slightly different physical and chemical properties, they commonly will be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. Natural terrestrial materials show a substantial variation in lithium isotopic abundance (Fig. IUPAC.3.1), and these natural isotopic abundances have been used to determine sources of dissolved lithium and to investigate environmental processes,. Variations in isotope-amount ratiosn(7Li)/n(6Li) can help determine the source of some water. Because the relative abundances of lithium isotopes can change during hydrothermal processes, isotopic analysis of lithium in water can help distinguish water derived from marine sedimentary rocks from water derived from hydrothermally altered igneous rocks (Fig. IUPAC.3.2),.
• 7Li, as hydroxide monohydrate (7LiOH•H2O), is used to maintain the pH level of the coolant used in pressurized water reactors in the nuclear power industry,. Lithium plays a role in the construction of a thermonuclear bomb, which differs from a fission weapon in that it uses the energy released when two light atomic nuclei (i.e. deuterium (2H) and tritium (3H)) fuse to form helium and a high energy neutronvia this DT reaction. 6Li is used, in the form of 6Li deuteride (6Li 2H), as fusion fuel capable of producing tritium when bombarded with neutrons within the weapon via the reaction 6Li (n, 3H) 4He. Li-based laboratory reagents have found their way into surface water and can be easily identified. Although a military secret in the 1950s, it is now known that substantial amounts of 6Li (normally having an isotopic abundance of 0.076) were removed from chemical reagents to be used in nuclear weapon development. Reagents containing the remaining lithium depleted in 6Li (having an isotopic abundance as low as 0.025) were sold to both chemical manufacturers and to laboratory chemists for their use. The distinctive isotopic signature of depleted 6Li, having a n(7Li)/n(6Li) ratio of 39, compared to a ratio of 12 in naturally occurring terrestrial materials, enables easier detection of this lithium source in polluted waterways and the environment,.
• 7Li is a decay product of the 10B (neutron, alpha) 7Li reaction, which has a peak value for room temperature neutrons. Brain tumor cells are typically found some 5 to 7 cm below the surface of the skull. After 10B has been introduced to or entered the tumor cells, a beam of neutrons of energy slightly above room temperature is introduced to the affected areas. The energy of these neutrons is reduced to room temperature by the time they react with the 10B, which then disintegrates into high energy charged particles (7Li and 4He), which deposit their kinetic energy in nearby (predominately cancerous) cells and destroys them. Any adjacent normal cells are unaffected.

Isotop litium lainnya

³Li, ⁴Li, ⁵Li, ⁶Li, ⁸Li, ⁹Li, ¹⁰Li, ¹¹Li, ¹²Li, ¹³Li

Pelajari

Kimia inti Simulasi peluruhan ⁷Li Bagan nuklida