1

### IIT-JEE 2008

STATEMENT - 1 : The plot of atomic number (y-axis) versus number of neutrons (x-axis) for stable nuclei shows a curvature towards x-axis from the line of 45o slope as the atomic number is increased.
STATEMENT - 2 : Proton-proton electrostatic repulsions begin to overcome attractive forces involving protons and neutrons in heavier nuclides
A
Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1
B
Statement - 1 is True, Statement - 2 is True; Statement - 2 is NOT a correct explanation for Statement - 1
C
Statement - 1 is true, Statement - 2 is False
D
Statement - 1 is False, Statement - 2 is True
2

### IIT-JEE 2008

Match the entries with column I with with the correctly related quantum number(s) in Column II.

Column I

(A) Orbital angular momentum of the electron in a hydrogen-like atomic orbital
(B) A hydrogen-like one-electron wave function obeying Pauli principle
(C) Shape, size and orientation of hydrogen like atomic orbitals
(D) Probability density of electron at the nucleus in hydrogen like atom

Column II

(p) Principal quantum number
(q) Azimuthal quantum number
(r) Magnetic quantum number
(s) Electron spin quantum number
A
(A) $\to$ q,r; (B) $\to$ p,q,r; (C) $\to$ p,q,r; (D) $\to$ q,r;
B
(A) $\to$ q,r; (B) $\to$ p,q,r,s; (C) $\to$ p,q; (D) $\to$ s,r;
C
(A) $\to$ r,s; (B) $\to$ p,q,r; (C) $\to$ p,q,r; (D) $\to$ p,q;
D
(A) $\to$ q,r; (B) $\to$ p,q,r,s; (C) $\to$ p,q,r; (D) $\to$ p,q;
3

### IIT-JEE 2007

This question contains STATEMENT-1 (Assertion) and STATEMENT-2 (Reason) and has 4 choices (a), (b), (c), (d) out of which ONLY ONE is correct.

STATEMENT-1 : Band gap in germanium is small. because
STATEMENT-2 : The energy gap of each germanium atomic energy level is infinitesimally small.
A
Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1
B
Statement - 1 is True, Statement - 2 is True; Statement - 2 is not a correct explanation for Statement - 1
C
Statement - 1 is True, Statement - 2 is False
D
Statement - 1 is False, Statement - 2 is True
4

### IIT-JEE 2006

According to Bohr's theory
En = Total energy, Kn = Kinetic Energy, Vn = Potential Energy, rn = Radius of nth orbit
Match the following

Column I

(A) Vn/Kn = ?
(B) If radius of nth orbit $\propto E_n^x,x = ?$
(C) Angular momentum in lowest orbital
(D) ${1 \over {{r_n}}} \propto {Z^y},y = ?$

Column II

(p) 0
(q) -1
(r) -2
(s) 1
A
(A) $\to$ r, (B) $\to$ p, (C) $\to$ q, (D) $\to$ s
B
(A) $\to$ r, (B) $\to$ q, (C) $\to$ p, (D) $\to$ s
C
(A) $\to$ s, (B) $\to$ p, (C) $\to$ q, (D) $\to$ r
D
(A) $\to$ p, (B) $\to$ r, (C) $\to$ q, (D) $\to$ s