소개
그룹: 없음
원자 무게: 231.03588
기간: 7
CAS 번호: 7440-13-3
분류
더 안정 동위 원소 없습니다
고체
액체
가스
고체 (예상)
기술 • 용도 / 기능
The first isotope of element 91 to be discovered was protactinium-234, also known as UX2, a short-lived member of the naturally occurring uranium-238 decay series. It was identified by K. Fajans and O. H. Gohring in 1913 and they named the new element brevium. When the longer-lived isotope protactinium-231 was identified by Hahn and Meitner in 1918, the name protoactinium was adopted as being more consistent with the characteristics of the most abundant isotope. Soddy, Cranson, and Fleck were also active in this work. The name protoactinium was shortened to protactinium in 1949. In 1927, Grosse prepared 2 mg of a white powder, which was shown to be Pa2O5. Later, in 1934, from 0.1 g of pure Pa2O5 he isolated the element by two methods, one of which was by converting the oxide to an iodide and “cracking” it in a high vacuum by an electrically heated filament by the decomposition of protactinium (V) iodide to protactinium and iodine. Protactinium has a bright metallic luster which it retains for some time in air. The element occurs in pitchblende to the extent of about 1 part protactinium-231 to 10 million of ore. Ores from Zaire have about 3 ppm. Protactinium has twenty four isotopes and isomers, the most common of which is protactinium-231 with a half-life of 32,500 years. A number of protactinium compounds are known, some of which are colored. The element is superconductive below 1.4 K. The element is a dangerous toxic material and requires precautions similar to those used when handling plutonium. In 1959 and 1961, it was announced that the Great Britain Atomic Energy Authority extracted by a 12-stage process 125 g of 99.9% protactinium, the world’s only stock of the metal for many years to come. The extraction was made from 60 tons of waste material at a cost of about $500,000. Protactinium is one of the rarest and most expensive naturally occurring elements. 1
물리적 특성
녹는 점:2* 1572 °C = 1845.15 K = 2861.6 °F
전자 구성: *[Rn] 7s2 5f3
n = 5
전기 음성도 (폴링 규모):4 1.5
비점:2*
승화 포인트:2
트리플 포인트:2
중요 포인트:2
밀도:3 15.4 g/cm3
* - at 1 atm
전자 구성
블록: f
최고 점유 에너지 레벨: 7
원자가 전자를: 2
양자 번호:
ℓ = 3
mℓ = -1
ms = +½
본딩
Electropositivity (폴링 규모): 2.5
이온화 전위
eV 5
kJ/mol
이온화 전위
eV 5
kJ/mol
이온화 전위
eV 5
kJ/mol
1
5.89
568.3
동위 원소
핵종
질량 6
하프 라이프 6
핵 스핀 6
에너지 바인딩
212Pa
212.02320(8)
8(5) ms [5.1(+61-19) ms]
7+#
1,621.29 MeV
213Pa
213.02111(8)
7(3) ms [5.3(+40-16) ms]
9/2-#
1,629.36 MeV
214Pa
214.02092(8)
17(3) ms
1,637.44 MeV
215Pa
215.01919(9)
14(2) ms
9/2-#
1,654.82 MeV
216Pa
216.01911(8)
105(12) ms
1,662.89 MeV
217Pa
217.01832(6)
3.48(9) ms
9/2-#
1,670.96 MeV
218Pa
218.020042(26)
0.113(1) ms
1,669.72 MeV
219Pa
219.01988(6)
53(10) ns
9/2-
1,687.11 MeV
220Pa
220.02188(6)
780(160) ns
1-#
1,685.86 MeV
221Pa
221.02188(6)
4.9(8) μs
9/2-
1,693.94 MeV
222Pa
222.02374(8)#
3.2(3) ms
1,702.01 MeV
223Pa
223.02396(8)
5.1(6) ms
1,710.08 MeV
224Pa
224.025626(17)
844(19) ms
5-#
1,718.15 MeV
225Pa
225.02613(8)
1.7(2) s
5/2-#
1,726.22 MeV
226Pa
226.027948(12)
1.8(2) min
1,734.29 MeV
227Pa
227.028805(8)
38.3(3) min
(5/2-)
1,742.36 MeV
228Pa
228.031051(5)
22(1) h
3+
1,741.12 MeV
229Pa
229.0320968(30)
1.50(5) d
(5/2+)
1,749.19 MeV
230Pa
230.034541(4)
17.4(5) d
(2-)
1,757.26 MeV
231Pa
231.0358840(24)
3.276(11)E+4 a
3/2-
1,765.33 MeV
232Pa
232.038592(8)
1.31(2) d
(2-)
1,773.40 MeV
233Pa
233.0402473(23)
26.975(13) d
3/2-
1,772.16 MeV
234Pa
234.043308(5)
6.70(5) h
4+
1,780.23 MeV
235Pa
235.04544(5)
24.44(11) min
(3/2-)
1,788.30 MeV
236Pa
236.04868(21)
9.1(1) min
1(-)
1,796.37 MeV
237Pa
237.05115(11)
8.7(2) min
(1/2+)
1,795.13 MeV
238Pa
238.05450(6)
2.27(9) min
(3-)#
1,803.20 MeV
239Pa
239.05726(21)#
1.8(5) h
(3/2)(-#)
1,811.27 MeV
240Pa
240.06098(32)#
2# min
1,810.03 MeV
값은 # 순수 실험 데이터에서 유래하지만, 적어도 부분적으로 체계적인 동향에서되지 않습니다 표시. 약한 할당 인수는 괄호로 묶와 함께 회전합니다. 6
풍부
지구 - 해수: 0.00000000005 mg/L 7
지구 -
빵 껍질:
0.0000014 mg/kg = 0.00000000014% 7
화합물
안전 정보
물질 안전 보건 자료 - ACI Alloys, Inc.
자세한 내용은
외부 링크:
American Elements
Chemical & Engineering News
Chemical Elements
ChemGlobe
Chemicool
Environmental Chemistry
소스
(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:25.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 4:132.
(3) - Lide, David R. CRC Handbook of Chemistry and Physics, 84th ed.; CRC Press: Boca Raton, FL, 2002; p 4:39-4:96.
(4) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 10:178 - 10:180.
(5) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:193, 12:219-220.
(6) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:123-6:137.
(7) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; pp 6:107-6:122.
(8) - Atomic Mass Data Center. http://amdc.in2p3.fr/web/nubase_en.html (accessed July 14, 2009).
(9) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 14:17.