# Braggs law to work out interplanar spacing d

• strugglin
In summary, you can use the Bragg's formula to calculate the interplanar spacing of KCl based on the de Broglie wavelength of electrons accelerated from rest by a voltage of 100V and the angle of the first diffraction peak. By rearranging the formula, you can easily solve for the interplanar spacing. In this case, the interplanar spacing is approximately 5.21 x 10^-10 m.
strugglin
hi, I've been bashing my head against the wall for the past few days trying to work this one out!
ive worked out a de broglie wavelength of electrons accelerated from rest by a voltage of 100v to be around (1.23 x 10 ^-10) m.
now using a KCl diffraction , these electrons cause a first diffraction peak at angle of 11.3 degrees...so therefore what is the interplanar spacing of the KCl??

im pretty sure the braggs formula has got to be implemented but unsure how??it couldn't be as simple as rearranging the bragg formula to get the d vaule could it?

2 d sin theta = n lambda

so basic info is that electrons are accelrated by 100v from rest
de broglie wavelength is (1.23 x 10 ^-10) m
and the first diffraction peak is at 11.3 degree angle

please, would apreciate ur ideas and help!

Yes, you can use the Bragg's formula to calculate the interplanar spacing of the KCl. The formula is 2d*sin(theta) = n*lambda, where d is the interplanar spacing, theta is the angle of incidence, n is an integer (usually 1 for the first peak), and lambda is the de Broglie wavelength. You can rearrange this equation to solve for d:d = n*lambda / (2*sin(theta))In your case, n = 1, lambda = 1.23 x 10^-10 m, and theta = 11.3 degrees. Plugging these numbers in, we get:d = 1*1.23 x 10^-10 m / (2*sin(11.3)) = 5.21 x 10^-10 m

## 1. What is Braggs law and how does it relate to interplanar spacing?

Braggs law is a fundamental principle in crystallography that describes the relationship between the diffraction angle of X-rays and the interplanar spacing of atoms within a crystal lattice. It states that when a beam of X-rays is incident upon a crystal, the X-rays will diffract off of the crystal planes at specific angles determined by the interplanar spacing.

## 2. How is Braggs law used to calculate interplanar spacing?

To calculate the interplanar spacing, the diffraction angle and the wavelength of the X-rays must be known. Braggs law can then be rearranged to solve for the interplanar spacing (d) using the equation: d = λ/(2sinθ), where λ is the wavelength of the X-rays and θ is the diffraction angle.

## 3. What factors can affect the accuracy of using Braggs law to calculate interplanar spacing?

Some factors that can affect the accuracy of using Braggs law to calculate interplanar spacing include the quality of the crystal sample, the intensity and wavelength of the X-ray beam, and the precision of the diffraction angle measurements. Imperfections in the crystal lattice, such as defects or strain, can also affect the accuracy of the calculations.

## 4. Can Braggs law be used for materials other than crystals?

While Braggs law was originally developed for crystals, it can also be applied to other periodic structures, such as thin films and diffraction gratings. However, the equation may need to be modified to account for the different properties of these materials.

## 5. How does knowing the interplanar spacing of a material contribute to scientific research?

Knowing the interplanar spacing of a material can provide valuable information about its structure and properties. This can help scientists in various fields, such as materials science and chemistry, to understand the behavior and characteristics of different materials. It can also aid in the development of new materials and technologies.

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