The number of electron and neturons of an element is 18 and 20 respectively. Its mass number is
2
17
37
38
The radius of hydrogen atom is 0.53 Å. The radius of 3Li2+ is of:
1.27 Å
0.17 Å
0.57 Å
0.99 Å
B.
0.17 Å
The radius of hydrogen atom = 0.53 Å.
3Li+2 ion consists of only 1 electron but it has 3 protons in its nucleus. Hence, its electron fall is three times more attracted from nucleus as compared to hydrogen atom. Thus, the radius of 3Li+2 is = = 0.17 Å
Wave nature of electrons was demonstrated by :
Schrodinger
de-Broglie
Davisson and Garmer
Heisenberg
4d, 5p, 5f and 6p orbitals are arranged in the order of decreasing energy. The correct option is:
6p > 5f > 5p > 4d
6p > 5f > 4d > 5p
5f > 6p > 4d > 5p
5f > 6p > 5p > 4d
Which of the following series of transitions in the spectrum of hydrogen atom fall in visible region?
Balmer series
Paschen series
Brackett series
Lyman series
Assertion (A) : Atoms with completely filled and half-filled sub-shells are stable.
Reason (R): Completely filled and half-filled sub-shells have symmetrical distribution of electrons and have maximum exchange energy.
The correct answer is
(A) and (R) are correct, (R) is the correct explanation of (A)
(A) and (R) are correct, (R) is not the correct explanation of (A)
(A) is correct, but (R)is not correct
(A) is not correct, but (R) is correct