The ionisation energy of gaseous Na atom is 495.8 text kJ text mol-1 . The lowest possible frequency of light that can ionise a Na atom is:

Question

The ionisation energy of gaseous Na atom is 495.8 text kJ text mol-1 . The lowest possible frequency of light that can ionise a Na atom is: (A)  1.24× 1012s-1  (B)  3.15× 1014s-1  (C)  4.76× 1014s-1  (D)  1.24× 1015s-1

Tardigrade Admin · Accepted Answer

E=hv , hence, v=(E/h) =(495.8× 103J/ textatom/6.02× 1023× 6.62× 10-34Js) =1.24× 1015s-1

Q. The ionisation energy of gaseous Na atom is $495.8 k J m o l^{- 1}$ . The lowest possible frequency of light that can ionise a Na atom is:

$1.24 \times 10^{12} s^{- 1}$

$3.15 \times 10^{14} s^{- 1}$

$4.76 \times 10^{14} s^{- 1}$

$1.24 \times 10^{15} s^{- 1}$

$E = h v$ , hence, $v = \frac{E}{h}$ $= \frac{495.8 \times 10 ^{3} J / atom}{6.02 \times 10 ^{23} \times 6.62 \times 10 ^{- 34} J s}$ $= 1.24 \times 10^{15} s^{- 1}$

Q. The ionisation energy of gaseous Na atom is 495.8kJmol−1 . The lowest possible frequency of light that can ionise a Na atom is:

1.24×1012s−1

3.15×1014s−1

4.76×1014s−1

1.24×1015s−1