According toMoseley's law, the frequency of a spectral line in X - ray spectrum varies asa)Atomic number of elementb)Square of atomic number of elementc)Square root of atomic number of elementd)Fourth power of atomic number of elementCorrect answer is option 'B'. Can you explain this answer?

Question

Answer

Moseley's law.
It states that the frequency of the spectral line in the characteristic X-ray spectrum is directly proportional to the square of the atomic number (Z) of the element considered.

Answer

Yes the graph is nu(frequency) vs √Z(atomic number). Moseley plotted this graph and obtained a straight line and hence concluded that periodic properties of an element are function of their atomic number and not atomic mass.

Answer

According to Moseley's law, the frequency of a spectral line in the X-ray spectrum varies as the square of the atomic number of the element. Let's understand this concept in detail.

Moseley's Law:
Moseley's law, also known as the Moseley's frequency rule, states that the square root of the frequency of an X-ray spectral line is directly proportional to the atomic number (Z) of the element. Mathematically, it can be represented as:

√f ∝ Z

where √f is the square root of the frequency and Z is the atomic number.

Explanation:
1. X-ray Spectra:
When a high-energy electron collides with an atom, it can cause inner-shell electrons to be ejected. These vacancies are then filled by outer-shell electrons, resulting in the emission of X-rays. These emitted X-rays form a characteristic X-ray spectrum for each element.

2. Atomic Number:
The atomic number of an element represents the number of protons in its nucleus. It determines the element's position in the periodic table and provides information about its electronic structure.

3. Relationship with Frequency:
Moseley's law establishes a relationship between the frequency of an X-ray spectral line and the atomic number of the element. According to the law, the square root of the frequency is directly proportional to the atomic number.

4. Square of Atomic Number:
Since the square root of the frequency is directly proportional to the atomic number, we can say that the frequency itself is directly proportional to the square of the atomic number. In other words, as the atomic number increases, the frequency of the X-ray spectral line increases, and vice versa.

Significance:
Moseley's law is significant because it provides a quantitative relationship between the atomic number of an element and the frequency of its X-ray spectral lines. This law helped in refining the periodic table by arranging the elements in increasing order of their atomic numbers rather than their atomic weights.

By understanding Moseley's law, scientists were able to establish a more accurate and consistent basis for the periodic table, which is widely used today. It also contributed to the development of X-ray spectroscopy and the understanding of atomic structure.

In conclusion, according to Moseley's law, the frequency of a spectral line in the X-ray spectrum varies as the square of the atomic number of the element. This law played a crucial role in refining the periodic table and advancing our understanding of atomic structure.

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