An electric bulb

We know ideal gas equation

PV=nRT

Where V= volume of gas

R=gas constant

T=temperature

n=number of moles of gas

P=pressure of gas.

Given

Volume of gas=250cc

1cc=1cm³m³

V=250m³

Pressure P=10^–3 mm of mercury

1mm of Hg= 133.32Pa

P= mm of Hg=133.32 Pa

Temperature T=27

T(K)=T ()+273.15

T=T(K)=27+273.15=300.15K

From ideal gas equation, we can write

Number of molecules = Avogadro numbernumber of moles

Number of molecules=n

=

Number of molecules in electric bulb=.