1
JEE Main 2025 (Online) 4th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
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Consider the ground state of chromium atom $(Z=24)$. How many electrons are with Azimuthal quantum number $l=1$ and $l=2$ respectively ?

A
16 and 5
B
12 and 5
C
12 and 4
D
16 and 4
2
JEE Main 2025 (Online) 4th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
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Which one of the following about an electron occupying the 1 s orbital in a hydrogen atom is incorrect?

(Bohr's radius is represented by $\mathrm{a}_0$)

A
The probability density of finding the electron is maximum at the nucleus
B
The total energy of the electron is maximum when it is at a distance $a_0$ from the nucleus
C
The electron can be found at a distance $2 a_0$ from the nucleus
D
The 1 s orbital is spherically symmetrical
3
JEE Main 2025 (Online) 3rd April Evening Shift
MCQ (Single Correct Answer)
+4
-1
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For electrons in ' 2 s ' and ' 2 p ' orbitals, the orbital angular momentum values, respectively are :

A
0 and $\sqrt{6} \frac{h}{2 \pi}$
B
0 and $\sqrt{2} \frac{h}{2 \pi}$
C
$\sqrt{2} \frac{h}{2 \pi}$ and 0
D
$\frac{h}{2 \pi}$ and $\sqrt{2} \frac{h}{2 \pi}$
4
JEE Main 2025 (Online) 3rd April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language
Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?
A
The electron in a H atom's stationary state moves in a circle around the nucleus.
B
An atom can take only certain distinct energies $\mathrm{E}_1, \mathrm{E}_2, \mathrm{E}_3$, etc. These allowed states of constant energy are called the stationary states of atom.
C
An atom in a stationary state does not emit electromagnetic radiation as long as it stays in the same state.
D
When an electron makes a transition from a higher energy stationary state to a lower energy stationary state, then it emits a photon of light.
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