Question

determine the longest wavelength of light required to remove an electron from a sample of potassium metal, if the binding energy for an electron in K is 1,76x10*3 kj/mol.

Answer 1

Answer:

The wavelength of light is 68 nm.

Explanation:

Given data:

Binding energy of electron = 176 × 10³ Kj/ mol or   (1.76× 10⁶ j/mol)

Wavelength of light require to remove the  electron = ?

Solution:

E = hc / λ

h = planck constant (6.63×10⁻³⁴ J/s)

c = speed of light = (3×10⁸ m/s)

The energy require per electron is

1.76 × 10⁶ j / 6.02× 10²³ = 2.92 × 10⁻¹⁸ J

Now we will put the values in formula,

E = hc / λ

λ =  hc / E

λ = 6.63×10⁻³⁴ m².kg.s⁻¹ . 3×10⁸ m/s / 2.92 × 10⁻¹⁸ J

λ = 19.89×10⁻²⁶ m /2.92 × 10⁻¹⁸   (m².kg.s⁻² = J)

λ = 6.8 ×10⁻⁸ m

λ = 6.8 ×10⁻⁸ × 10⁹

λ = 68 nm

Answer 2

$E = hc / wavelength\\h = (6.63* 10^{-34} J/s)\\c = (3* 10^{8} m/s)$

The energy require per electron is

$1.76 * 10^{8} j / 6.02* 10^{23} = 2.92 * 10^{-18} J$

Now we will put the values in formula,

E = hc / λ

λ =  hc / E  

$Wavelength = 6.63* 10_{*34} m^{2} .kg.s^{-1} . 3×10^{8} m/s / 2.92 × 10^{-18} J\\Wavelength = 6.8 *10^{-8} * 10^{9} \\Wavelength = 68 nm$

Thus, the longest wavelength is 68nm.

Learn more about wavelength calculation: https://brainly.com/question/19156861