JEE Mains · Physics · STD 12 - 12. atoms
In a hydrogen like ion, the energy difference between the \(2^{\text {nd }}\) excitation energy state and ground is 108.8 eV. The atomic number of the ion is
- A 4
- B 2
- C 1
- D 3
Answer & Solution
Correct Answer
(D) 3
Step-by-step Solution
Detailed explanation
\(\Delta \mathrm{E}=13.6 \mathrm{z}^2\left[\frac{1}{\mathrm{n}_1^2}-\frac{1}{\mathrm{n}_2^2}\right]\) \((13.6) \mathrm{z}^2\left[\frac{1}{1}-\frac{1}{9}\right]=108.8\) \(\frac{(13.6)(8)}{9}\left(z^2\right)=108.8\) \(\mathrm{z}=3\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A rigid massless road of length \(3l\) has tow masses attached at each end as shown in the figure. The rod is pivoted at point \(P\) on the horizontal axis (see figure). When released from initial horizontal position, its instantaneous angular acceleration will be
JEE Mains 2019 Hard - A galvanometer of resistance \(100 \Omega\) when connected in series with \(400 \Omega\) measures a voltage of upto \(10 \mathrm{~V}\). The value of resistance required to convert the galvanometer into ammeter to read upto \(10 \mathrm{~A}\) is \(\mathrm{x} \times 10^{-2} \Omega\). The value of \(\mathrm{x}\) is _______.JEE Mains 2024 Hard
- A plane electromagnetic wave of frequency \(500\, MHz\) is travelling in vacuum along \(y-\)direction. At a particular point in space and time, \(\overrightarrow{ B }=8.0 \times 10^{-8} \hat{ z } \;T\). The value of electric field at this point is (speed of light \(\left.=3 \times 10^{8}\, ms ^{-1}\right)\) \(\hat{ x }, \hat{ y }, \hat{ z }\) are unit vectors along \(x , y\) and \(z\) direction.JEE Mains 2021 Medium
- Hydrogen atom is bombarded with electrons accelerated through a potential different of \(\mathrm{V}\), which causes excitation of hydrogen atoms. If the experiment is being formed at \(\mathrm{T}=0 \mathrm{~K}\). The minimum potential difference needed to observe any Balmer series lines in the emission spectra will be \(\frac{\alpha}{10} \mathrm{~V}\), where \(\alpha=\) _______.JEE Mains 2024 Hard
- A solid sphere is rolling on a horizontal plane without slipping. If the ratio of angular momentum about axis of rotation of the sphere to the total energy of moving sphere is \(\pi: 22\) then, the value of its angular speed will be \(...........\,rad / s\).JEE Mains 2023 Medium
- A parallel plate capacitor of area \(60\, cm^2\) and separation \(3\, mm\) is charged initially to \(90\, \mu C\). If the medium between the plate gets slightly conducting and the plate loses the charge initially at the rate of \(2.5\times10^{-8}\, C/s\), then what is the magnetic field between the plates ?JEE Mains 2013 Medium
More PYQs from JEE Mains
- Match the List-I with List-II
Choose the correct answer from the options given below:List-I List-II A. Magnetic induction I. \(M L T ^{-2} A^{-2}\) B. Magnetic flux II. \(ML ^2 T^{-2} A^{-2}\) C. Magnetic permeability III. \(ML ^0 T^{-2} A^{-1}\) D. Self inductance IV. \(ML ^2 T^{-2} A^{-1}\) JEE Mains 2026 Hard - A stationary horizontal disc is free to rotate about its axis. When a torque is applied on it, its kinetic energy as a function of \(\theta ,\) where \(\theta \) is the angle by which it has rotated, is given as \(k\theta ^2.\) If its moment of inertia is \(I\) then the angular acceleration of the disc isJEE Mains 2019 Hard
- A man on the top of a vertical tower observes a car moving at a uniform speed towards the tower on a horizontal road. If it takes \(18\) min, for the angle of depression of the car to change from \(30^o\) to \(45^o,\) then after this, the time taken (in min) by the car to reach the foot of the tower, isJEE Mains 2018 Hard
- Let \(y = y(x)\) be the solution of the differential equation \((\tan x)^{1/2}\,dy = (\sec^3 x - (\tan x)^{3/2} y)\,dx\), \(0 < x < \dfrac{\pi}{2}\), \(y\left(\dfrac{\pi}{4}\right) = \dfrac{6\sqrt{2}}{5}\). If \(y\left(\dfrac{\pi}{3}\right) = \dfrac{4}{5}\alpha\), then \(\alpha^4\) equals _______.JEE Mains 2026 Hard
- The minimum number of elements that must be added to the relation \(R =\{( a , b ),( b , c )\}\) on the set \(\{a, b, c\}\) so that it becomes symmetric and transitive is:JEE Mains 2023 Hard
- A quantity Q is formulated as \(\mathrm{X}^{-2} \mathrm{Y}^{+\frac{3}{2}} \mathrm{Z}^{-\frac{2}{5}} \cdot \mathrm{X}, \mathrm{Y}\) and Z are independent parameters which have fractional errors of \(0.1,0.2\) and 0.5 , respectively in measurement. The maximum fractional error of Q is _______.JEE Mains 2025 Medium