6th HW 1.23 What is KeV?

$\lambda=\frac{h}{p}$

Louise Zhuang
Posts: 31
Joined: Fri Sep 28, 2018 12:28 am

6th HW 1.23 What is KeV?

What is KeV? When you see it as the unit of energy, do you use E=hv or lamba=h/p?

Problem: 1.23 The y-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these y-rays.

Meachelle_Lum_1I
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Joined: Fri Sep 28, 2018 12:24 am

Re: 6th HW 1.23 What is KeV?

eV= electric Volt
kEv is like "kilo" electric Volt so just multiply that number by 1,000.
The conversion for volts to joules is 1eV=1.602*10^-19 Joules.

tierra parker 1J
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Re: 6th HW 1.23 What is KeV?

eV = electric volt which is the amount of energy in an electron
KeV = kilo-electric volt so multiply that quantity by 10^3
there is 1.602 x 10^-19 J = 1 eV
then you would proceed by using E = hc/lambda

Sona Hakobyan 3J
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Joined: Fri Sep 28, 2018 12:25 am

Re: 6th HW 1.23 What is KeV?

You need to know the following equations and conversions:
KeV = kilo-electric volt (multiply quantity by 1000)
1.602 x 10^-19 J = 1 eV
E = hc/lambda

Alan Chang
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Joined: Fri Sep 28, 2018 12:29 am

Re: 6th HW 1.23 What is KeV?

It is an unit of energy called an kilo-electronvolt.
One KeV is 1000 eV, and 1 eV = 1.602 × 10-19 J
Its on the Constants and Equations page that can be found on the class website! :)

Kevin Tang 4L
Posts: 83
Joined: Fri Sep 28, 2018 12:28 am

Re: 6th HW 1.23 What is KeV?

In order to do this problem, you need to convert keV (kiloelectronvolt) to joules.
There are 6.242x10^15 keV in 1 joule:

140.511keV*(1 joule/ 6.242x10^15)= 2.251x10^-14 joules