Properties of Helium
a. Atomic no 2
b. Viscosity is zero.
c. Used in COPD
d. used in gas chromatography
e. is heavier than air
Ans.
(A) Atomic no 2; (B) Viscosity is zero;
(C) Used in COPD (D). used in gas chromatography
• Helium is one of the noble gas with the atomic number of
2. It has monatomic molecules, and is the lightest of all gases except hydrogen.
• it has no freezing point, and
its viscosity is apparently zero; it passes readily through
minute cracks and pores and will even creep up the sides and over the lip of a
container.
• Helium is
the second most abundant element in the
universe, after hydrogen; however, it is rare on Earth, primarily found mixed with natural gas trapped in
underground pockets.
Uses:
• Because it is noncombustible, helium is preferred to
hydrogen as the lifting gas in lighter-than- air balloons.
• Used in inert gas arc welding for light metals such as aluminum and magnesium alloys that might otherwise oxidize; the helium protects heated parts from attack by air.
• Used in inert gas arc welding for light metals such as aluminum and magnesium alloys that might otherwise oxidize; the helium protects heated parts from attack by air.
•Used in place of nitrogen as part of the synthetic
atmosphere breathed by deep-sea divers (SCUBA), caisson workers, and others,
because it reduces susceptibility to the bends.
• Helium with Oxygen (HELIOX) used in medicine to relieve
sufferers of respiratory difficulties because helium moves more easily than
nitrogen through constricted respiratory passages as in COPD & bronchial
asthma.
• In Surgery, beams of ionized helium from synchrocyclotron
sources are proving useful in treating eye tumors, by stabilizing or even
shrinking the tumors. Such beams are also used to shrink blood-vessel
malformations in the brains of patients.
• Helium can be inhaled and visually detected via MRI, which
produces high-contrast images of the body’s soft tissues. The use of helium is
a departure from traditional MRI, which typically distinguishes body tissues
from one another by tracking differences in water content.
