Calculate the velocity of an electron placed in the 2nd orbit of the Li2+ ion,. Also calculate the no. of revolutions per second that it makes around the nucleus.

The velocity of an electorn in nth shell of the hydrogen like atom is ((2.18*10^6)*Z)/n. Putting Z=3(atomic no of lithium) and n=2,

=(2.18*10^6)*3/2

=(3.27*10^6)ms^-1.

No of revolution per second 2(pi)r/v where r=(0.529*(n^2))/Z)*10^-10

r=2(pi)((0.529*n^2)/Z)*10^-10

r=2(pi)((0.529*4)/3)*10^-10=(4.42*10^-10)m

Time=(4.42*10^-10)m/(3.27*10^6)ms^-1=1.35*10^-16   

No of revolutions is 1/T=.74*10¹⁶

Approved