Orbitals

Q.

Why does an electron not fall in the nucleus?

Q.

What is nodal plane and explain it's features

Q. The wave number of the first line of Balmer series of hydrogen is 15200/cm.The wave number of the first Balmer line of Li2+ ion is- (A)15200/cm (B)60800/cm (C)76000/cm (D)136800/cm

Q.

What is penetration effect?

Q.

Differences between atomic orbital and molecular orbital.

Q. When the first electron gain enthalpy $\left({\Delta }_{eg}H\right)$ of oxygen is $-141kJ/mol,$ its second electron gain enthalpy is:

1. Almost the same as that of the first
2. Negative, but less negative than the first
3. A positive value
4. A more negative value than the first

Q.

Find the no. Of waves in 5 orbit of an atom.

Q. Which of the following has highest electron gain enthalpy?
(A) $\left[Ne\right]3s^{2}3p^3$
(B) $\left[Ne\right]3s^{2}3p^4$
(C) $\left[Ne\right]3s^{2}3p^5$
(D) $\left[Ne\right]3s^{2}3p^2$

1. (A)
2. (B)
3. (C)
4. (D)

Q. Which of the following molecules has the largest extent of back bonding?

1. $B{I}_3$
2. $BC{l}_3$
3. $BB{r}_3$
4. $B{F}_3$

Q. What is the maximum number of electrons in an atom that can have n = 4 and magnetic quantum number = +1?

Q. The radial probability distribution curve Obtain for an orbital. wave function () has 3 peaks nd 2 radial nodes. The valence e- of which one of the following metal dpes this wave function () correspond to? (1) Co (2) Li (3) K (4) Na

Q.

What is the difference between atomic orbital and molecular orbital?

Q. What exactly penetrating effect means ?

Q. Statement I: The $5^{th}$ period of the periodic table contains 18 elements and not 32.
Statement II: $n=5,l=0,1,2and3$. The order in which the energy of the orbitals 4d, 5s and 5p increases is $5s<4d<5p$. The total number of orbitals available are 9 and thus, 18 electrons can be accomodated.

1. Both the statements are true and Statement II is a correct explanation of Statement I
2. Both the statements are true and Statement II is not a correct explanation of Statement I
3. Statement (I) is true and Statement (II) is false
4. Statement (I) is false and Statement (II) is true

Q. Ratio of radii of orbits in two different orbits of $H-$ atom is $4:9$, then possible ratio of energy for these two orbits is:

1. $2:3$
2. $3:2$
3. $2:9$
4. $9:4$

Q. How to find the orbital when wave function is given in values (n, l, m)?

Q. According to Bohr theory, the angular momentum of electron in $5^{th}$ orbit is

1. 
2. 
3. 
4. 

Q. $pi$ bonds is formed by the overlapping of

1. p-p orbital’s along their axis
2. s-p orbital’s along the axis of p-orbital’s
3. s-s orbital’s
4. p-p orbital’s perpendicular to their axis

Q. Statement I: The $5^{th}$ period of the periodic table contains 18 elements and not 32.
Statement II: $n=5,l=0,1,2and3$. The order in which the energy of the orbitals 4d, 5s and 5p increases is $5s<4d<5p$. The total number of orbitals available are 9 and thus, 18 electrons can be accomodated.

1. Both the statements are true and Statement II is a correct explanation of Statement I
2. Both the statements are true and Statement II is not a correct explanation of Statement I
3. Statement (I) is true and Statement (II) is false
4. Statement (I) is false and Statement (II) is true

Q. The absolute value of the electron gain enthalpy of halogens satisfies:

1. $Cl>Br>F>I$
2. $I>Br>Cl>F$
3. $F>Cl>Br>I$
4. $Cl>F>Br>I$

Q. The impossible overlap among the following is:

1. 
2. 
3. 
4. 

Q.

Describe the number of Orbitals ?

Q.

What are Atomic orbitals?

Q. Differentiate between Orbit and Orbital.

Q. Which of the following molecules has the largest extent of back bonding?

1. $B{F}_3$
2. $BC{l}_3$
3. $B{I}_3$
4. $BB{r}_3$

Q. Which of the following statements regarding an orbital are correct?

1. An orbital is the region around the nucleus where is 90 - 95% probability of finding an electron of an atom
2. An orbital is a definite trajectory around the nucleus in which electron can move
3. An orbital always has spherical trajectory
4. An orbital is characterized by 3 quantum numbers n, l and m

Q. Distinguish between orbit and orbital.

Q. Select the correct statement(s) out of the following:
i) A sigma (s) bond is formed when two s-orbitals overlap.
ii) A pi (p) bond is formed when two p-orbitals overlap sideways.
iii) An sigma bond is weaker than pi bond.

1. i and ii
2. ii and iii
3. i only
4. ii only

Q. Among following molecule $N-Si$ bond length is shortest:

1. $N(Si{H}_3{)}_3$
2. $NH(Si{H}_3{)}_2$
3. $N{H}_2\left(Si{H}_3\right)$
4. $\text{All have equal}N-Si\text{bond length}$

Q. Calculate the wave number of the second line in Balmer series