Radium-228 (²²⁸Ra)

Data nuklida

Unsur

Radium (Ra, Z = 88)

Nomor massa (A)

228

Proton (Z)

88

Neutron (N)

140

Massa atom

228.031068574 ± 0.000002141 u

Waktu paruh

5,75 tahun (± 0,03 tahun)

Mode peluruhan

Peluruhan beta minus (β⁻) ( 100 %)

Inti anak

Aktinium-228 (²²⁸Ac)

Tahun penemuan

1907

Sumber data

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

Kegunaan isotop radium

• The radioactive isotopes 223Ra (with a half-life of 275 h), 224Ra (with a half-life of 88 h), 226Ra (with a half-life of 1600 years), and 228Ra (with a half-life of 5.75 years) are used as tracers to determine water flow rates. They are ideal environmental tracers because they behave conservatively once released into a water mass (meaning only mixing and decay processes affect their distribution). The activity ratios A(224Ra)/A(223Ra), A(223Ra)/A(226Ra), A(224Ra)/A(228Ra), and A(228Ra)/A(226Ra) have been used in lake studies to monitor and detect water inflow and mixing, to determine sources of inflowing water, and to monitor introduced water masses as they move within a body of water (i.e. a lake),. For example, submarine groundwater discharge is an important pathway that transports dissolved substances from aquifers below a seabed to the coastal ocean. Submarine groundwater discharge can be difficult to quantify because it is both spatially and temporally variable. As a result, its relative importance in coastal ocean chemical budgets is commonly poorly known. Peterson et al. used an hourly time series of measurements of multiple radium isotopes 223Ra, 224Ra, and 226Ra to quantify submarine groundwater discharge. They also used 222Rn (with a half-life of 3.8 days) measurements to independently quantify submarine groundwater discharge.
• 226Ra and 228Ra can be used for dating materials up to a few thousand years in age because the half-lives of 226Ra and 228Ra are 1600 years and 5.75 years, respectively, even though the long-lived 226Ra is found in nature as a result of its continuous production by the decay of 238U. For example, long-lived 226Ra has been used to date a limestone cave in central Switzerland, corals in the Indian Ocean, and Pleistocene gravel terraces. The activity ratio A(224Ra)/A(223Ra) is a potential age calculator for old lake water because the low 223Ra and 224Ra activities in old lake water are relatively unaffected by mixing.

Isotop radium lainnya

²⁰¹Ra, ²⁰²Ra, ²⁰³Ra, ²⁰⁴Ra, ²⁰⁵Ra, ²⁰⁶Ra, ²⁰⁷Ra, ²⁰⁸Ra, ²⁰⁹Ra, ²¹⁰Ra, ²¹¹Ra, ²¹²Ra, ²¹³Ra, ²¹⁴Ra, ²¹⁵Ra, ²¹⁶Ra, ²¹⁷Ra, ²¹⁸Ra, ²¹⁹Ra, ²²⁰Ra, ²²¹Ra, ²²²Ra, ²²³Ra, ²²⁴Ra, ²²⁵Ra, ²²⁶Ra, ²²⁷Ra, ²²⁹Ra, ²³⁰Ra, ²³¹Ra, ²³²Ra, ²³³Ra, ²³⁴Ra, ²³⁵Ra

Pelajari

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