Question

Calculate energy of an electron
having wavelength of 0.72 Å.​

Answer 1

$\mathtt{ \huge{ \fbox{Solution :)}}}$

Given ,

Wavelength = 0.72 Å

We know that ,

$\large \mathtt{{ \fbox{Energy = \frac{h \times c}{ wavelength} }}}$

Where ,

• h = Planck's constant
• c = Velocity of light

Substitute the known values , we get

$\sf \mapsto Energy = \frac{6.626 \times {(10)}^{ - 34} \times 3 \times {(10)}^{8} }{0.72} \\ \\ \sf \mapsto Energy = \frac{6626 \times 3 \times {(10)}^{ (- 34 + 8 + 2)} }{72} \\ \\ \sf \mapsto Energy = \frac{19878 \times {(10)}^{ - 24} }{72} \\ \\ \sf \mapsto Energy = 276.083 \times {(10)}^{ - 24} \: \: joule</p><p>$

Hence , the energy of an electron is 276.083 × (10)^-24 joule

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