09-15-2021-0421 - Hydrogen-4 through Hydrogen-7

 

Hydrogen-4[edit]

⁴H (atomic mass 4.02643(11) Da) contains one proton and three neutrons in its nucleus. It is a highly unstable isotope of hydrogen. It has been synthesized in the laboratory by bombarding tritium with fast-moving deuterium nuclei.^[14] In this experiment, the tritium nucleus captured a neutron from the fast-moving deuterium nucleus. The presence of the hydrogen-4 was deduced by detecting the emitted protons. It decays through neutron emission into hydrogen-3 (tritium) with a half-life of 139(10) ys (or 1.39(10)×10⁻²² s).

In the 1955 satirical novel The Mouse That Roared, the name quadium was given to the hydrogen-4 isotope that powered the Q-bomb that the Duchy of Grand Fenwick captured from the United States.^{[citation needed]}

Hydrogen-5[edit]

⁵H (atomic mass 5.035311(96) Da) is a highly unstable isotope of hydrogen. The nucleus consists of a proton and four neutrons. It has been synthesized in the laboratory by bombarding tritium with fast-moving tritium nuclei.^[14][15] In this experiment, one tritium nucleus captures two neutrons from the other, becoming a nucleus with one proton and four neutrons. The remaining proton may be detected, and the existence of hydrogen-5 deduced. It decays through double neutron emission into hydrogen-3 (tritium) and has a half-life of 86(6) ys (8.6(6)×10⁻²³ s).

Hydrogen-6[edit]

⁶H (atomic mass 6.04496(27) Da) decays either through triple neutron emission into hydrogen-3 (tritium) or quadruple neutron emission into hydrogen-2 (deuterium) and has a half-life of 294(67) ys (2.94(67)×10⁻²² s).

Hydrogen-7[edit]

⁷H (atomic mass 7.05275(27) Da) consists of a proton and six neutrons. It was first synthesized in 2003 by a group of Russian, Japanese and French scientists at RIKEN's Radioactive Isotope Beam Factory by bombarding hydrogen with helium-8 atoms. In the resulting reaction, all six of the helium-8's neutrons were donated to the hydrogen's nucleus. The two remaining protons were detected by the "RIKEN telescope", a device composed of several layers of sensors, positioned behind the target of the RI Beam cyclotron.^[2] Hydrogen-7 has a half life of 2.3 x 10^-14 ns ^[16] (= 2.3 x 10^-23 s or 23 ys), which is the shortest half-life known for any isotope of any element (see List of radioactive nuclides by half-life).

Reference from: https://en.wikipedia.org/wiki/Isotopes_of_hydrogen#Hydrogen-1_(Protium)