You can search for things like...

Plutonium
Electrons Per Shell of Curium
Ge (Symbol of Germanium)
106 (Atomic Number of Seaborgium)
Ionization Energies of Oganesson in J/mol

At

Astatine

Properties

Isotopes

Electrons

39 known isotopes (0 stable, 39 radioactive)

Show stable only

¹⁹¹At

Mass

191.004148 u

Abundance

—

Half-life

1.7 milliseconds

Spin/Parity

(1/2+)

Decay Mode(s)

α (100%)

¹⁹²At

Mass

192.003141 u

Abundance

—

Half-life

88 milliseconds

Spin/Parity

(9- 10-)

Decay Mode(s)

α (100%)

¹⁹³At

Mass

192.999928 u

Abundance

—

Half-life

28 milliseconds

Spin/Parity

(1/2+)

Decay Mode(s)

α (100%)

¹⁹⁴At

Mass

193.999231 u

Abundance

—

Half-life

286 milliseconds

Spin/Parity

(4- 5-)

Decay Mode(s)

α (100%), SF+EC+B+ (0.8%)

¹⁹⁵At

Mass

194.996274 u

Abundance

—

Half-life

290 milliseconds

Spin/Parity

(1/2+)

Decay Mode(s)

α (100%)

¹⁹⁶At

Mass

195.995799 u

Abundance

—

Half-life

0.388 seconds

Spin/Parity

(3+)

Decay Mode(s)

α (95.1%), EC/β⁺ (4.9%)

¹⁹⁷At

Mass

196.993177 u

Abundance

—

Half-life

0.388 seconds

Spin/Parity

(9/2-)

Decay Mode(s)

α (96.1%), EC/β⁺ (3.9%)

¹⁹⁸At

Mass

197.992798 u

Abundance

—

Half-life

4.2 seconds

Spin/Parity

(3+)

Decay Mode(s)

α (90%), EC/β⁺ (10%)

¹⁹⁹At

Mass

198.990528 u

Abundance

—

Half-life

7.03 seconds

Spin/Parity

(9/2-)

Decay Mode(s)

α (90%), EC/β⁺ (10%)

²⁰⁰At

Mass

199.990351 u

Abundance

—

Half-life

43 seconds

Spin/Parity

(3+)

Decay Mode(s)

α (52%), EC/β⁺ (48%)

²⁰¹At

Mass

200.988417 u

Abundance

—

Half-life

87.6 seconds

Spin/Parity

9/2-

Decay Mode(s)

α (71%), EC/β⁺ (29%)

²⁰²At

Mass

201.988626 u

Abundance

—

Half-life

184 seconds

Spin/Parity

(2+ 3+)

Decay Mode(s)

EC/β⁺ (63%), α (37%)

²⁰³At

Mass

202.986943 u

Abundance

—

Half-life

7.4 m

Spin/Parity

9/2-

Decay Mode(s)

EC/β⁺ (69%), α (31%)

²⁰⁴At

Mass

203.987251 u

Abundance

—

Half-life

9.12 m

Spin/Parity

Decay Mode(s)

EC/β⁺ (96.09%), α (3.91%)

²⁰⁵At

Mass

204.986061 u

Abundance

—

Half-life

26.9 m

Spin/Parity

9/2-

Decay Mode(s)

EC/β⁺ (90%), α (10%)

²⁰⁶At

Mass

205.986646 u

Abundance

—

Half-life

30.6 m

Spin/Parity

(5)+

Decay Mode(s)

EC/β⁺ (99.1%), α (0.9%)

²⁰⁷At

Mass

206.985800 u

Abundance

—

Half-life

1.81 h

Spin/Parity

9/2-

Decay Mode(s)

EC/β⁺ (91.4%), α (8.6%)

²⁰⁸At

Mass

207.986613 u

Abundance

—

Half-life

1.63 h

Spin/Parity

Decay Mode(s)

EC/β⁺ (99.45%), α (0.55%)

²⁰⁹At

Mass

208.986169 u

Abundance

—

Half-life

5.42 h

Spin/Parity

9/2-

Decay Mode(s)

EC/β⁺ (95.9%), α (4.1%)

²¹⁰At

Mass

209.987147 u

Abundance

—

Half-life

8.1 h

Spin/Parity

(5)+

Decay Mode(s)

EC/β⁺ (99.825%), α (0.175%)

²¹¹At

Mass

210.987496 u

Abundance

—

Half-life

7.214 h

Spin/Parity

9/2-

Decay Mode(s)

Electron capture (58.2%), α (41.8%)

²¹²At

Mass

211.990737 u

Abundance

—

Half-life

0.314 seconds

Spin/Parity

(1-)

Decay Mode(s)

α (100%)

²¹³At

Mass

212.992937 u

Abundance

—

Half-life

125 nanoseconds

Spin/Parity

9/2-

Decay Mode(s)

α (100%)

²¹⁴At

Mass

213.996372 u

Abundance

—

Half-life

558 nanoseconds

Spin/Parity

Decay Mode(s)

α (100%)

²¹⁵At

Mass

214.998651 u

Abundance

—

Half-life

0.10 milliseconds

Spin/Parity

9/2-

Decay Mode(s)

α (100%)

²¹⁶At

Mass

216.002423 u

Abundance

—

Half-life

0.30 milliseconds

Spin/Parity

Decay Mode(s)

α (100%), β⁻ (0.006%), Electron capture (3e-7%)

²¹⁷At

Mass

217.004718 u

Abundance

—

Half-life

32.6 milliseconds

Spin/Parity

9/2-

Decay Mode(s)

α (99.993%), β⁻ (0.007%)

²¹⁸At

Mass

218.008696 u

Abundance

—

Half-life

1.28 seconds

Spin/Parity

(3- 2-)

Decay Mode(s)

α (99.95%), β⁻ (0.05%)

²¹⁹At

Mass

219.011161 u

Abundance

—

Half-life

56 seconds

Spin/Parity

(9/2-)

Decay Mode(s)

α (93.6%), β⁻ (6.4%)

²²⁰At

Mass

220.015433 u

Abundance

—

Half-life

3.71 m

Spin/Parity

Decay Mode(s)

β⁻ (92%), α (8%)

²²¹At

Mass

221.018017 u

Abundance

—

Half-life

2.3 m

Spin/Parity

—

Decay Mode(s)

β⁻ (100%)

²²²At

Mass

222.022494 u

Abundance

—

Half-life

54 seconds

Spin/Parity

—

Decay Mode(s)

β⁻ (100%)

²²³At

Mass

223.025151 u

Abundance

—

Half-life

50 seconds

Spin/Parity

—

Decay Mode(s)

β⁻ (100%)

²²⁴At

Mass

224.029749 u

Abundance

—

Half-life

1.3 m

Spin/Parity

—

Decay Mode(s)

Unknown

²²⁵At

Mass

225.032528 u

Abundance

—

Half-life

300 nanoseconds

Spin/Parity

—

Decay Mode(s)

Unknown

²²⁶At

Mass

226.037209 u

Abundance

—

Half-life

300 nanoseconds

Spin/Parity

—

Decay Mode(s)

Unknown

²²⁷At

Mass

227.040183 u

Abundance

—

Half-life

300 nanoseconds

Spin/Parity

—

Decay Mode(s)

Unknown

²²⁸At

Mass

228.044960 u

Abundance

—

Half-life

300 nanoseconds

Spin/Parity

—

Decay Mode(s)

Unknown

²²⁹At

Mass

229.048191 u

Abundance

—

Half-life

300 nanoseconds

Spin/Parity

—

Decay Mode(s)

Unknown

Decay mode abbreviations:

β⁻ = Beta minus decay, β⁺ = Beta plus decay, EC = Electron capture, α = Alpha decay

n = Neutron emission, p = Proton emission, SF = Spontaneous fission, IT = Isomeric transition

Conversions Print

Name

Atomic Mass

Series

Metals

Nonmetals