Helium-4

	Email		Print
	Bookmark		Link

Helium-4

Helium-4 ( or ) is a non-radioactive and light isotope

Isotope

Isotopes are any of the different types of atoms of the same chemical element, each having a different atomic mass . Isotopes of an element have atomic nucleus with the same number of protons but different numbers of neutron....
of helium

Helium

Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2....
. It is by far the most abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is a boson

Boson

In particle physics, bosons are subatomic particle which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein....
and an alpha particle

Alpha particle

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium atomic nucleus; hence, it can be written as He2+ or 42He2+....
, having two proton

Proton

The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom but is also stable by itself and has a second identity as the hydrogen ion, H+....
s and two neutron

Neutron

The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.Neutrons are usually found in atomic nucleus....
s. Alpha decay

Alpha decay

Alpha decay is a type of radioactivity decay in which an atomic nucleus emits an alpha particle and transforms into an atom with a mass number 4 less and atomic number 2 less....
is a common decay mode for many radioactive isotopes. In fact, alpha decay of heavy elements is the source of most naturally occurring helium-4 on earth.

Discussion

Ask a question about 'Helium-4'

Start a new discussion about 'Helium-4'

Answer questions from other users

Full Discussion Forum

Encyclopedia

Helium-4 ( or ) is a non-radioactive and light isotope

Isotope

Helium

Boson

In particle physics, bosons are subatomic particle which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein....
and an alpha particle

Alpha particle

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium atomic nucleus; hence, it can be written as He2+ or 42He2+....
, having two proton

Proton

Neutron

The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.Neutrons are usually found in atomic nucleus....
s. Alpha decay

Alpha decay

Nuclear fusion

In nuclear physics and nuclear chemistry, nuclear fusion is the process by which multiple like-charged atomic nuclei join together to form a heavier nucleus....
in star

Star

A star is a massive, luminous ball of Plasma that is held together by its own gravity. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth....
s and during the Big Bang.

When helium-4 is cooled to below 2.17 kelvin

Kelvin

The kelvin is a Units of measurement of temperature and is one of the seven SI base units. The Kelvin scale is a Thermodynamic temperature scale where absolute zero, the theoretical absence of all thermal energy, is zero ....
s (–271 °C), it becomes a superfluid

Superfluid

Superfluidity is a phase or description of heat capacity in which unusual effects are observed when liquids, typically of helium-4 or helium-3, overcome friction by surface interaction when at a stage at which the liquid's viscosity becomes zero....
, with properties that are very unlike those of an ordinary liquid. For example, if helium-4 is kept in an open vessel, a thin film will climb up the sides of the vessel and overflow. Another name for this property of Helium is Rollin film

Rollin film

A Rollin film, named after Bernard V. Rollin, is a 30 nanometre-thick liquid film of helium in the helium II state. It exhibits a "creeping" effect in response to surfaces extending past the film's level ....
. This strange behaviour is a result of the Clausius-Clapeyron relation

Clausius-Clapeyron relation

The Clausius-Clapeyron relation, named after Rudolf Clausius and ?mile Clapeyron, who defined it sometime after 1834, is a way of characterizing the phase transition between two phases of matter, such as solid and liquid....
and cannot be explained by the current model

Model (physical)

A physical model is a smaller or larger physical copy of an object. The object being modelled may be small or large .The geometry of the model and the object it represents are often similar in the sense that one is a rescaling of the other; in such cases the Scale is an important characteristic....
of classical mechanics

Classical mechanics

Classical mechanics is used for describing the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies....
nor by nuclear

Nuclear physics

Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei.The most commonly known applications of nuclear physics are nuclear power and nuclear weapons, but the research field is also the basis for a far wider range of applications, including in the medical sector , in materials engineering...
or electrical models; it is only understood as a quantum mechanical

Quantum mechanics

Quantum mechanics is a set of principles underlying the most fundamental known description of all physical systems at the microscopic scale . Notable amongst these principles are both a dual wave-like and particle-like behavior of matter and radiation, and prediction of probabilities in situations where classical physics predicts certaintie...
phenomenon.