Through what potential difference δv must electrons be accelerated (from rest) so that they will have the same wavelength as an x-ray of wavelength 0.120 nm ? use 6.63×10−34 j⋅s for planck's constant, 9.11×10−31 kg for the mass of an electron, and 1.60×10−19 c for the charge on an electron. express your answer using three significant figures. view available hint(s) δv δ v deltav = 104 v submitprevious answers correct significant figures feedback: your answer 104.7 v was either rounded differently or used a different number of significant figures than required for this part. part b through what potential difference δv must electrons be accelerated so they will have the same energy as the x-ray in part a? use 6.63×10−34 j⋅s for planck's constant, 3.00×108 m/s for the speed of light in a vacuum, and 1.60×10−19 c for the charge on an electron. express your answer using three significant figures.

A) 105 V

The De Broglie wavelength of an electron is given by

where

is the Planck constant

p is the electron's momentum

Solving for p and using

we find

The (kinetic) energy of the electron is related to the momentum, p, by the formula

where

m = 9.11×10−31 kg

is the electron's mass

So we calculate the energy of the electron:

The energy acquired by an electron moving through a potential difference of is

where

is the electron charge

Solving the formula for and using the energy of the photon we found previously, we get

B)

First of all, let's calculate the energy of the x-ray photon, given by:

where

is the Planck constant

is the speed of light

is the wavelength

Substituting,

The energy acquired by an electron moving through a potential difference of is

where

is the electron charge

Solving the formula for and using the energy of the photon we found previously, we get

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

no

sodium is solid at rt