Question

Radium disintegrates at an average rate of 2.24×10^13 alpha particles per minute. Each alpha particle takes up two electrons from the air and becomes a neutral helium atom. After 420 days helium gas collected was 0.5mL, measured at 27°c and 750mmHg. Calculate the Avogadro Constant. Answer is 6.7×10^23​

Answer 1

let the avagadro constant be A

number of alpha particle after 420 days =2.24*10^13*420*24*60 helium ion

=1.35*10^6*10^13 helium ion

=1.35*10^19 helium ion

now mole of helium atom

n=PV/RT

=750/760)*(.5*10^-3)/.0821*300

=2*10^-5

2*10-5 mole contain 1.35*10^19 helium atom

1 mole will have 1.35*10^19/2*10^-5

=.675*10^24

=6.75*10^23 helium atom which is the avagadro constant

Answer 2

Answer:

sequel ka matlab bhi nahi pata