Propeies of Helium

D i.e. All Helium (He) has no freezing point, approximately zero (0) viscosity, atomic number 2 and atomic weight 4.006Q. It is second most lightest gas (after hydrogen) and 2nd most abundant element in universe, after hydrogen. However, it is rare on eah. It solidifies at - 272. 20degC at pressure above 26 atm; & boils at - 268.9degC. Its density is 0.1664 g/lit at 20degc & 1 atm. It is used with 02 as HELIOX in COPD & bronchial asthmaQ. Inhaled helium is used in MRI to produce high contrast images. And beams of He from synchrocyclotron are used in eye tumors for shrinking it and for vascular malformation.