Modern Periodic Law and Table
Periods, groups, s, p, d and f blocks and nomenclature of elements above 100. (Chemistry › Classification of Elements and Periodicity in Properties, NEET UG syllabus.)
What is Modern Periodic Law and Table?
The physical and chemical properties of elements are periodic functions of their atomic numbers.
Key formula / rule: General Electronic Configuration of s-block elements
Key points
- State and explain the Modern Periodic Law.
- Describe the structure of the Modern Periodic Table, including periods and groups.
- Classify elements into s, p, d, and f blocks based on their electronic configuration and position.
- Write the general electronic configuration for elements in each block.
Common exam trap
Confusing Modern Periodic Law with Mendeleev's Periodic Law (based on atomic mass).
Definitions
- Term
Modern Periodic Law
- Meaning
The physical and chemical properties of elements are periodic functions of their atomic numbers.
- Term
Period
- Meaning
A horizontal row in the periodic table, representing elements with the same principal quantum number (n) for their outermost electron shell.
- Term
Group
- Meaning
A vertical column in the periodic table, containing elements with similar valence shell electronic configurations and thus similar chemical properties.
- Term
Block (s, p, d, f)
- Meaning
A classification of elements based on the type of atomic orbital (s, p, d, or f) that receives the last differentiating electron in their electronic configuration.
- Term
IUPAC Nomenclature for Z > 100
- Meaning
A systematic method for naming elements with atomic numbers greater than 100 using numerical roots corresponding to each digit of the atomic number, followed by the suffix '-ium'.
Learning objectives
State and explain the Modern Periodic Law.
Describe the structure of the Modern Periodic Table, including periods and groups.
Classify elements into s, p, d, and f blocks based on their electronic configuration and position.
Write the general electronic configuration for elements in each block.
Apply IUPAC nomenclature rules to name elements with atomic number greater than 100.
Relate the position of an element in the periodic table to its electronic configuration and general properties.
Formulae
- Name
General Electronic Configuration of s-block elements
- Note
n = period number
- Expression
ns¹⁻²
- Name
General Electronic Configuration of p-block elements
- Note
n = period number
- Expression
ns²np¹⁻⁶
- Name
General Electronic Configuration of d-block elements (Transition elements)
- Note
n = period number
- Expression
(n-1)d¹⁻¹⁰ns¹⁻²
- Name
General Electronic Configuration of f-block elements (Inner Transition elements)
- Note
n = period number
- Expression
(n-2)f¹⁻¹⁴(n-1)d⁰⁻¹ns²
Prerequisites
Basic understanding of atomic structure (protons, neutrons, electrons).
Knowledge of electronic configuration of elements (Aufbau principle, Hund's rule, Pauli exclusion principle).
Familiarity with quantum numbers (principal, azimuthal, magnetic, spin).
Common mistakes
Confusing Modern Periodic Law with Mendeleev's Periodic Law (based on atomic mass).
Incorrectly identifying the block of an element based on its position or electronic configuration.
Errors in applying IUPAC nomenclature rules for elements with Z > 100, especially digit-to-root mapping.
Mistaking the number of periods for the number of groups or vice-versa.
Not understanding that elements in the same group have similar chemical properties due to similar valence shell electronic configurations.
Keywords
Modern Periodic Law
Atomic Number
Moseley
Periodic Table
Period
Group
s-block
p-block
d-block
f-block
Electronic Configuration
IUPAC Nomenclature
Valence Electrons
Practice preview
How many periods are there in the long form of the Modern Periodic Table?…
easy
An element with the electronic configuration [Ar] 3d⁵ 4s² belongs to which block in the Modern Periodic Table?…
medium
Who proposed the Modern Periodic Law, stating that the physical and chemical properties of elements are a periodic function of their atomic numbers?…
easy