1
JEE Main 2020 (Online) 5th September Morning Slot
MCQ (Single Correct Answer)
+4
-1
The difference between the radii of 3rd and 4th
orbits of Li2+ is R1 . The difference between the
radii of 3rd and 4th orbits of He+ is $$\Delta $$R2 .
Ratio $$\Delta $$R1 : $$\Delta $$R2 is :
A
8 : 3
B
3 : 2
C
2 : 3
D
3 : 8
2
JEE Main 2020 (Online) 5th September Morning Slot
MCQ (Single Correct Answer)
+4
-1
The correct electronic configuration and spin-only
magnetic moment (BM) of Gd3+ (Z = 64), respectively, are
A
[Xe]5f7 and 8.9
B
[Xe]4f7 and 7.9
C
[Xe]5f7 and 7.9
D
[Xe]4f7 and 8.9
3
JEE Main 2020 (Online) 5th September Morning Slot
MCQ (Single Correct Answer)
+4
-1
In the sixth period, the orbitals that are filled are :
A
6s, 5d, 5f, 6p
B
6s, 4f, 5d, 6p
C
6s, 6p, 6d, 6f
D
6s, 5f, 6d, 6p
4
JEE Main 2020 (Online) 4th September Evening Slot
MCQ (Single Correct Answer)
+4
-1
The shortest wavelength of H atom in the Lyman series is $$\lambda $$1. The longest wavelength in the Balmar series of He+ is :
A
$${{5{\lambda _1}} \over 9}$$
B
$${{36{\lambda _1}} \over 5}$$
C
$${{27{\lambda _1}} \over 5}$$
D
$${{9{\lambda _1}} \over 5}$$
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