Long Form of Periodic Table — Revision Notes

⚡ 30-Second Revision

Modern Periodic Law: — Properties are periodic functions of atomic number (Z).
Periods: — 7 horizontal rows, highest 'n' in config. ($1s^2 \rightarrow$ Period 1, $2s^2 \rightarrow$ Period 2, etc.)
Groups: — 18 vertical columns, similar valence e- config, similar properties.
Blocks:

- s-block (Gr 1, 2): Last e- in s-orbital. $ns^{1-2}$. Reactive metals. - p-block (Gr 13-18): Last e- in p-orbital. $ns^2np^{1-6}$. Metals, non-metals, metalloids. - d-block (Gr 3-12): Last e- in d-orbital. $(n-1)d^{1-10}ns^{1-2}$. Transition metals, variable oxidation states, colored ions. - f-block (Lanthanides, Actinides): Last e- in f-orbital. $(n-2)f^{1-14}(n-1)d^{0-1}ns^2$. Inner transition metals, placed separately.

IUPAC Nomenclature (Z > 100): — Use roots (un=1, bi=2, tri=3, nil=0, etc.) + '-ium' suffix. E.g., $Z=112 \rightarrow$ Ununbium (Uub).

2-Minute Revision

The long form of the periodic table organizes elements by increasing atomic number, following the Modern Periodic Law. It features 7 periods (horizontal rows), where the period number corresponds to the highest principal quantum number of the valence shell.

There are 18 groups (vertical columns), with elements in the same group sharing similar chemical properties due to identical valence electron configurations.

s-block (Groups 1 & 2): — Alkali and alkaline earth metals, highly reactive, $ns^{1-2}$ configuration.
p-block (Groups 13-18): — Contains metals, non-metals, and metalloids, $ns^2np^{1-6}$ configuration.
d-block (Groups 3-12): — Transition metals, characterized by variable oxidation states, colored ions, and catalytic properties, $(n-1)d^{1-10}ns^{1-2}$ configuration.
f-block (Lanthanides & Actinides): — Inner transition metals, placed separately, filling $4f$ or $5f$ orbitals.

For elements with atomic numbers greater than 100, a systematic IUPAC nomenclature is used, combining numerical roots (e.g., 'un' for 1, 'bi' for 2, 'nil' for 0) with the suffix '-ium' (e.g., Ununbium for Z=112). This structure is fundamental for understanding periodic trends and inorganic chemistry.

5-Minute Revision

A thorough understanding of the long form of the periodic table is crucial for NEET. It's built on the Modern Periodic Law, which states that element properties are periodic functions of their atomic numbers. This resolved issues with Mendeleev's atomic mass-based table.

Structure:

Periods (7 rows): — Determined by the highest principal quantum number ($n$) of the valence shell. For example, elements in Period 3 have their outermost electrons in the 3rd shell. The number of elements in each period varies (2, 8, 8, 18, 18, 32, 32).
Groups (18 columns): — Elements in a group share similar chemical properties due to identical valence electron configurations. For instance, Group 1 elements ($ns^1$) are alkali metals, and Group 17 elements ($ns^2np^5$) are halogens.

Blocks:

s-block (Gr 1, 2): — Last electron enters an s-orbital. Highly reactive metals, low ionization enthalpy, form ionic compounds. Example: Na ($[Ne]3s^1$) is in Period 3, Group 1, s-block.
p-block (Gr 13-18): — Last electron enters a p-orbital. Diverse properties, includes metals, non-metals, and metalloids. Example: Cl ($[Ne]3s^23p^5$) is in Period 3, Group 17, p-block.
d-block (Gr 3-12): — Last electron enters a $(n-1)d$ orbital. Transition metals. High melting points, variable oxidation states, form colored ions, good catalysts. Example: Fe ($[Ar]3d^64s^2$) is in Period 4, Group 8, d-block.
f-block (Lanthanides & Actinides): — Last electron enters an $(n-2)f$ orbital. Inner transition metals, placed separately. Many are radioactive. Example: Pm ($[Xe]4f^56s^2$) is in Period 6, Group 3 (conventionally), f-block.

IUPAC Nomenclature for Z > 100: Use numerical roots for digits (0=nil, 1=un, 2=bi, 3=tri, 4=quad, 5=pent, 6=hex, 7=sept, 8=oct, 9=enn) followed by '-ium'. For Z=104, it's Unnilquadium (Unq). This is a temporary name until an official name is approved.

Key Takeaway: To master this, practice determining period, group, and block from atomic number/configuration, and memorize IUPAC naming rules. Understand the general characteristics of each block, as these form the basis for periodic trends and inorganic chemistry questions.

Prelims Revision Notes

The long form of the periodic table is based on the Modern Periodic Law, which states that the physical and chemical properties of elements are periodic functions of their atomic numbers (Z). This replaced Mendeleev's atomic mass basis, resolving anomalies.

Structure:

Periods (7): — Horizontal rows. The period number equals the highest principal quantum number ($n$) of the valence shell. For example, elements with $n=4$ are in Period 4. Number of elements per period: 2, 8, 8, 18, 18, 32, 32.
Groups (18): — Vertical columns. Elements in the same group have similar outermost electronic configurations and thus similar chemical properties.

Blocks: Determined by the subshell where the last electron enters.

s-block (Groups 1 & 2): — Outer configuration $ns^{1-2}$. Alkali metals (Gr 1) and Alkaline Earth metals (Gr 2). Highly reactive, low IE, strong reducing agents, form ionic compounds.
p-block (Groups 13-18): — Outer configuration $ns^2np^{1-6}$. Contains metals, non-metals, and metalloids. Properties vary widely. Group 17 (halogens) are highly reactive non-metals; Group 18 (noble gases) are inert.
d-block (Groups 3-12): — Last electron enters $(n-1)d$ orbital. Transition metals. High melting/boiling points, variable oxidation states, form colored ions, paramagnetic, good catalysts, form complexes.
f-block (Lanthanides & Actinides): — Last electron enters $(n-2)f$ orbital. Inner transition metals. Placed separately below the main table. Lanthanides (Z=58-71, $4f$ series); Actinides (Z=90-103, $5f$ series). Many actinides are radioactive.

Determining Position:

1
Period: — Highest 'n' in electronic configuration.
2
Block: — Subshell of last electron (s, p, d, f).
3
Group:

* s-block: Number of valence electrons. * p-block: 10 + number of valence electrons. * d-block: (Electrons in $(n-1)d$) + (Electrons in $ns$). * f-block: Conventionally Group 3.

IUPAC Nomenclature for Z > 100:

Digits: 0=nil, 1=un, 2=bi, 3=tri, 4=quad, 5=pent, 6=hex, 7=sept, 8=oct, 9=enn.
Combine roots in order of digits, add '-ium' suffix. E.g., Z=101 $ightarrow$ Unnilunium (Unu); Z=118 $ightarrow$ Ununoctium (Uuo).

Common Mistakes to Avoid: Confusing atomic mass with atomic number, miscounting valence electrons, incorrect group rules for d-block, and misplacing f-block elements.

Vyyuha Quick Recall

To remember the IUPAC roots for Z > 100: Un Bi Tri Quad Pent Hex Sept Oct Enn Nil. (1, 2, 3, 4, 5, 6, 7, 8, 9, 0) - Just remember the order and the first letter of each root.