Modern Periodic Law And The Present Form Of The Periodic Table

The correct option is (b) noble gas

Explanation:

The outermost electronic configuration of an element with atomic number 118 is 7s²7p⁶. Since its electronic configuration in the outermost orbit, ns²np⁶ resembles inert or noble gases therefore it will be a noble gas element.

The electronic configuration of an element with atomic number 118 will be [Rn]5f¹⁴6s²6p⁶. The element with the atomic number 118, will be a noble gas.

Alternate Approach

Elements with different atomic numbers have different electronic configurations that enables us to understand the positions of these elements in the periodic table. A periodic table contains elements grouped in different blocks such as s, p, d, and f.

Complete answer:

The atomic number of an element of a chemical element is the number of electrons present in the neutral species. 

• Electronsof an atom or molecule distribute themselves in an atomic or molecular orbital. 
• This distribution refers to electronic configuration. 
• The electronic configuration provides an insight into the chemical behaviour of elements and their position in the periodic table.

Characteristics of noble gases 

Noble gases are odourless, non-flammable, colourless, and monoatomic gas with low chemical reactivity.

• All the noble gases conduct electricity and fluorescence which can be needed in many conditions to maintain a constant and safe environment.
• All noble gases are insoluble in water.
• As they have a complete octet which makes them highly stable. So, they hardly react with other elements to form chemical bonds because of their low tendencies to either gain or lose electrons. 
• But exceptions are everywhere. Xenonis a noble gas that may form compounds either with fluoride or oxide

Further the important steps for determining electronic configuration we

• Shells: Electronic configuration of an element with atomic number will be [Rn]5f¹⁴6d1⁶7s²7p⁶.
• Subshells: Its electronic configuration in the outermost orbit (ns²np⁶)
• Notations: This resembles that of inert or noble gases such as Argon[Ne]3s²3p⁶.

Thus, it will be a noble gas element. Therefore, option (B) is the correct option i.e. Noble Gas.

Note: Note that we also analyze and solve the question by considering Radon which is a noble gas, also which has atomic number 86 When 32 electrons are added to it, we get the element with atomic number 118. Since, in the seventh period, a maximum of 32 electrons can be accommodated. Hence, an element with atomic number 118 is a noble gas.

The third ionization enthalpy refers to the energy required to remove an electron from a doubly positively charged ion. In the case of gadolinium (Gd), this process is influenced by several factors. The correct reason for gadolinium having a low third ionization enthalpy is its high exchange enthalpy. This is because:

1. Electron Configuration: Gadolinium's electron configuration is [Xe] 4f⁷ 5d¹ 6s². Removing electrons involves disrupting a stable half-filled f-orbital.

2. Exchange Enthalpy: The 4f orbitals in gadolinium are half-filled, which offers stability due to the exchange energy. Exchange energy results from the half-filled or fully filled subshell, leading to stability due to parallel spins allowing for maximum exchange interactions among electrons.

3. Energetic Favorability: To maintain this stable state upon ionization requires less energy compared to disrupting a configuration that does not support exchange stabilization.

Based on the factors above, the low third ionization enthalpy in gadolinium can be attributed to the high exchange enthalpy provided by the half-filled 4f orbital.

To achieve the nearest noble gas configuration, elements tend to gain or lose electrons in their outermost shell. Let's consider the electron configurations of the given elements:

F (Fluorine): Atomic number 9 Electron configuration: 1s² 2s² 2p⁵
N (Nitrogen): Atomic number 7 Electron configuration: 1s² 2s² 2p³
Na (Sodium): Atomic number 11 Electron configuration: 1s² 2s² 2p⁶ 3s¹
O (Oxygen): Atomic number 8 Electron configuration: 1s² 2s² 2p⁴

Nitrogen needs to gain three electrons to achieve the noble gas configuration of neon (1s² 2s² 2p⁶). Nitrogen forms largest in achieve the nearest noble gas configuration.
Therefore, The correct option is (B): N

Let's match each quantum number with the information it provides:

(A) m_l (Magnetic Quantum Number):

The magnetic quantum number (m_l) describes the spatial orientation of an orbital. It determines the number of orbitals and their orientation within a subshell.

Therefore, (A) matches with (III) Orientation of orbital.

(B) m_s (Spin Quantum Number):

The spin quantum number (m_s) describes the intrinsic angular momentum of an electron, which is also called spin angular momentum. It specifies the orientation of the spin of an electron.

Therefore, (B) matches with (IV) Orientation of spin of electron.

(C) l (Azimuthal Quantum Number):

The azimuthal quantum number (l) determines the shape of an orbital and the subshell to which an electron belongs. It can have values from 0 to n-1.

Therefore, (C) matches with (I) Shape of orbital.

(D) n (Principal Quantum Number):

The principal quantum number (n) determines the size of an orbital and the energy level to which an electron belongs. It can have positive integer values (1, 2, 3, ...).

Therefore, (D) matches with (II) Size of orbital.

Matching Summary:

(A) - (III)

(B) - (IV)

(C) - (I)

(D) - (II)

Electronegativity generally increases across a period from left to right and decreases down a group.

1. Silicon (Si): Silicon is in Group 14 and is below carbon. It has the lowest electronegativity among the given elements because it is further down the group.

2. Carbon (C): Carbon is in Group 14 and has a higher electronegativity than silicon because it is higher up in the group.

3. Nitrogen (N): Nitrogen is in Group 15 and has a higher electronegativity than carbon due to its position to the right of carbon in the same period.

4. Oxygen (O): Oxygen is in Group 16 and has a higher electronegativity than nitrogen because it is further to the right in the same period.

5. Fluorine (F): Fluorine is in Group 17 and has the highest electronegativity among the given elements because it is the furthest to the right in the period.

Therefore, the increasing order of electronegativity is:

Si < C < N < O < F

Conclusion:

The correct order is Si < C < N < O < F

Step 1: Identify the Group Numbers of Each Cation

• Al³⁺: This is a Group III cation.
• Cu²⁺: This is a Group II cation.
• Ba²⁺: This is a Group II cation.
• Co²⁺: This is a Group VII cation.
• Mg²⁺: This is a Group II cation.

Step 2: Arrange Them in Increasing Group Number

The correct order based on increasing group number is:

• B (Cu²⁺) ¡ A (Al³⁺) ¡ D (Co²⁺) ¡ C (Ba²⁺) ¡ E (Mg²⁺)

Step 3: Conclusion

The correct answer is:

Option (1): B, A, D, C, E