Which noble gas is used for filling balloons for meteorological observations?

Which noble gas is used in filling balloons for meteorological observations ?

(i) Which allotrope of phosphorus is more reactive and why?. (ii) How are the supersonic jet aeroplanes responsible for the depletion of ozone layer ? (iii) F_(2) has lower bond dissociation epthalpy than Cl_(2) . Why? (iv) Which noble gas is used in filling balloons for meteorological observations? (v) Complete the following equation : XeF_(2)+PF_(5)rarr

Which noble gas is used in filling balloons for meteorological obersvation ?

(i) Which allotrope of phosphorus is more reactive and why ? (ii) How are the supersonic jet aeroplanes responsible for the depletion of ozone layers ? (iii) F_(2) has lower bond dissociation enthalpy than Cl_(2) . Why ? (iv) While noble gas is used in filling balloons for meterological observations ?

Name the gas used in : filling balloons

Helium is heavier than hydrogen. Yet helium is used (instead of H_(2) ) in filling baloons for meteorological observations - Why ?