Principle Quantum Number

Q. ________ quantum number describes the size and energy of the shell.

1. Principal
2. Magnetic
3. Spin
4. Angular momentum

Q.

The factor not affecting ionisation enthalpy is:

1. Charge in the nucleus

2. Type of bonding in the crystal lattice

3. Type of electron involved

4. Size of atom

Q. The maximum number of electrons that are present in $\text{K}$ shell of an atom is ______.

1. two
2. eight
3. thirty two
4. sixteen

Q.

What are Quantum Numbers ?

Q.

Paragraph for below question
नीचे दिये गये प्रश्न के लिए अनुच्छेद

According to the quantum mechanical model of atom, the electronic distribution of an atom containing a number of electrons is divided into shells. The shells, in turn are thought to consist of one or more subshells and subshells are assumed to be composed of one or more orbitals, which the electrons occupy. The electrons are filled in those orbitals in order of increasing energy in accordance with Pauli exclusion principle and Hund’s rule of maximum multiplicity.

परमाणु के क्वांटम यांत्रिकी प्रतिरूप के अनुसार, बहु इलेक्ट्रॉनों वाले परमाणु में इलेक्ट्रॉनीय वितरण कोशों में विभाजित होता है। यह माना जाता है कि कोश एक या अधिक उपकोशों से बने होते हैं तथा उपकोश एक या अधिक कक्षकों से बने होते हैं जिनमें इलेक्ट्रॉन ग्रहण किए जाते हैं। इलेक्ट्रॉन उन कक्षकों में भरे जाते हैं जो पाउली के अपवर्जन सिद्धान्त तथा हुण्ड की अधिकतम बहुलकता के अनुसार ऊर्जा के बढ़ते क्रम में हों।

Q. For Be³⁺ ion, the correct order of energy of atomic orbitals is

प्रश्न - Be³⁺ आयन के लिए, परमाणवीय कक्षकों की ऊर्जा का सही क्रम है

1. 5f = 4f > 5d = 4d > 5p = 4p
2. 5f > 4f > 5d > 4d > 5p > 4p
3. 5f = 5d = 5p > 4f = 4d = 4p
4. 5f > 5d > 4f > 5p > 4d > 4p

Q. What is the number of unpaired electrons in a manganese atom ($Z=25$) in its lowest energy states?

1. $1$
2. $3$
3. $7$
4. $5$

Q. Only one electron in the outermost shell of an atom has the following set of quantum numbers: $n=2,l=0$. The atom belongs to which of the following elements?

1. Lithium
2. Beryllium
3. Boron
4. Hydrogen

Q. The angular momentum of electron in a shell is quantized, was derived by Bohr.

1. True
2. False

Q. Paragraph for below question
नीचे दिए गए प्रश्न के लिए अनुच्छेद

The energy of an electron in a multi-electron atom, unlike that of the hydrogen atom, depends not only on its principal quantum number but also on its azimuthal quantum number. That is, for a given principal quantum number, s, p, d, f… subshells have different energies. The main reason for having different energies of the subshells is the mutual repulsion among the electrons in multi-electron atoms.

हाइड्रोजन परमाणु के विपरीत एक बहुइलेक्ट्रॉनीय परमाणु में इलेक्ट्रॉन की ऊर्जा केवल इसकी मुख्य क्वाण्टम संख्या पर ही निर्भर नहीं करती बल्कि इसकी द्विगंशी क्वाण्टम संख्या पर भी निर्भर करती है। इसलिए एक दी गयी मुख्य क्वाण्टम संख्या के लिए s, p, d, f… उपकोशों की ऊर्जाएं भिन्न-भिन्न होती हैं। उपकोशों की भिन्न भिन्न ऊर्जाओं का मुख्य कारण बहुइलेक्ट्रॉनीय परमाणु में इलेक्ट्रॉनों में पारस्परिक प्रतिकर्षण है।

Q. The correct order of energy of the given orbitals in multi-electronic species is

प्रश्न - बहुइलेक्ट्रॉनीय स्पीशीज में दिए गए कक्षकों की ऊर्जा का सही क्रम है

1. 4f > 5d > 5p > 4d
2. 5d > 5p > 4d > 4f
3. 5d > 4f > 5p > 4d
4. 5d > 5p > 4f > 4d

Q. In the long form of the periodic table, the valance shell electronic configuration of $5s^{2}5p^4$ corresponds to the element present in :

1. Group 17 and period 6
2. Group 17 and period 5
3. Group 16 and period 5
4. Group 16 and period 6

Q.

Following is the information about some particles.

Elements	Mass number	Atomic number	Number of electrons
P	24	12	12
Q	35	17	17
R	37	17	17
S	20	10	10
T	23	11	10
V	19	9	10

a)

i) Name the particle which is a metal_____

ii)Give a reason for your answer in a) i)

b)

i)Name two particles which are non metals______

ii)Give reason for your answer in b) i)

c) Name the particle which is chemically inactive and state reason for your choice.

d)Name the particle which is positively charged and state reason for your choice.

e)Name the particle which is negatively charged and state reason for your choice.

f)State the formula of the molecule formed by the union of

(i) Q only

(ii) P and Q

(iii)T and V.

Q. Which of the following elements have two electrons in its K shell?

1. Hydrogen
2. Helium
3. Sodium
4. Aluminium

Q. An element has an atomic number 19. How many electrons are there in K, L, M, N shells of its atom?

1. 2, 8, 8, 1
2. 2, 7, 8, 2
3. 3, 7, 7, 2
4. 3, 7, 8, 1

Q. What does principal quantum number represents?
[2 marks]

Q.

The quantum numbers for an electron in the outermost orbital of an element are given as $n=2,l=0,m=0,s=-\frac{1}{2}$. The atom could be:

1. Lithium

2. Beryllium

3. Hydrogen

4. Boron