The energy of a photon emitted during a transition is related to its wavelength by:
\( E = \frac{hc}{\lambda} \)
where \( h \) is Planck's constant, \( c \) is the speed of light, and \( \lambda \) is the wavelength.
From the equation above, we can see that for the shortest wavelength (\( \lambda_{min} \)), the energy (\( E \)) must be maximum.
The energy of a photon emitted during a transition is equal to the difference in energy levels:
\( E = E_{initial} - E_{final} \)
The largest energy difference corresponds to the shortest wavelength. In the given diagram:
The energy levels in a hydrogen atom are given by:
\( E_n = -\frac{13.6 \text{ eV}}{n^2} \)
We can see that transitions C and D are identical in the provided image and diagram, which is likely an error in the original question. Assuming D is meant to be the transition from \( n = 3 \) to \( n = 1 \), D represents the largest energy difference, followed by C (which is the same as D, again suggesting an error), then B, and finally A.
The transition corresponding to the emission of the shortest wavelength is D (assuming it is intended to represent the transition from \( n = 3 \) to \( n = 1 \)) (Option 2).
Let \( ABC \) be a triangle. Consider four points \( p_1, p_2, p_3, p_4 \) on the side \( AB \), five points \( p_5, p_6, p_7, p_8, p_9 \) on the side \( BC \), and four points \( p_{10}, p_{11}, p_{12}, p_{13} \) on the side \( AC \). None of these points is a vertex of the triangle \( ABC \). Then the total number of pentagons that can be formed by taking all the vertices from the points \( p_1, p_2, \ldots, p_{13} \) is ___________.
Consider the following two reactions A and B: 
The numerical value of [molar mass of $x$ + molar mass of $y$] is ___.
Consider an A.P. $a_1,a_2,\ldots,a_n$; $a_1>0$. If $a_2-a_1=-\dfrac{3}{4}$, $a_n=\dfrac{1}{4}a_1$, and \[ \sum_{i=1}^{n} a_i=\frac{525}{2}, \] then $\sum_{i=1}^{17} a_i$ is equal to