Question

Be sure to answer all parts.

Cobalt−60 is a radioactive isotope used to treat cancers of the brain and other tissues. A gamma ray emitted by an atom of this isotope has an energy of 9.70 MeV (million electron volts; 1 eV = 1.602×10⁻¹⁹ J). What is the frequency (in Hz) and the wavelength (in m) of this gamma ray?

Enter your answers in scientific notation.

Frequency:

2.35 x 10^21 Hz (IS CORRECT)

Wavelength:

1.28 x 10^? m (1.28 IS CORRECT, but what is the power?)

Answer 1

Energy = 9.7 Mev

       = 9.7*10^6*1.602*10^-19

       = 1.554*10^-12 joule

E = hv

E = 1.554*10^-12 joule

h = planks constant = 6.625*10^-34 j.s

v = frequency = E/h = (1.554*10^-12)/(6.625*10^-34)

   = 2.35*10^21 Hz

E = hc/L

E = 1.554*10^-12 joule

h = planks constant = 6.625*10^-34 j.s

c = light velocity = 3*10^8 m/s

L = wave length = ?

(1.554*10^-12) = (6.625*10^-34)*(3*10^8)/L

L = 1.28*10^-13 m