Trouble with chemistry question??

Question

Here's the question:

 

Different materials are used in X-ray tubes to produce Xray for different applications. The table lists the frequencies of different materials that might be used in an X-ray tube.

 

Material                    Frequency (Hz)

- - - - -                     - - - - - - - - - -

Cobalt                       1.67 x 10^18

 

Copper                      1.95 x 10^18

 

Molybdenum              4.23 x 10^17

 

 

What is the energy of photons given off in an X-ray tube that contains molybdenum, in units of 1 x 10^-16 J?

Answer 1

For this problem, we need to use Planck's equation: E=hv, where E is energy h is Planck's constant, and v is frequency.

 

h= 6.63 x 10^-34 J*s

v= 4.23 x 10¹⁷ Hz (which is s^-1)

 

E= (6.63 x 10^-34 J*s)* 4.23 x 10¹⁷ s^-1

 

From here, it's just calculation and using the correct number of significant figures.