The ionisation energy of gaseous sodium atom is 495.80 kJ per mole. The lowest possible frequency of light that can ionise a sodium atom is how much? The options for the above question are:- 1.4.76*10 raised to power 14 per second, 2. 7.50*10 raised to power 14 per second, 3. 1.2410 raised to power 15 per second and 4. 3.15*10 raised to power 15 per second. Which of the following is correct among the given four options and how?.....Please give me the answer as soon as possible....

Asked by Pragnya Kar | 29th May, 2014, 12:24: PM

Expert Answer:

Ionisation energy per atom = 495.80 x 103J mol-1 = 8.233 x10-19J

6.022x1023 mol-1

E = h ν

ν = E = 8.233x10-19 J = 1.24 X1015 s-1

h 6.626x10-34J.s

Answered by Vaibhav Chavan | 30th May, 2014, 09:22: AM