<span>the heated filament will react with the oxygen in the air but now with the argon, which is a noble gas and hardly ever reacts.</span>
Taking specific heat of lead as 0.128 J/gK = c
We have energy of ball at 7.00 meter height = mgh = 
When leads gets heated by a temperature ΔT energy needed = mcΔT
=
ΔT
Comparing both the equations
=
ΔT
ΔT = 0.536 K
Change in temperature same in degree and kelvin scale
So ΔT = 0.536 
The earth is so round that we can run around it in five million days