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Interactive Periodic Table

All 118 elements, colour-coded by category. Tap any element to see atomic number, mass, electron configuration, melting/boiling point and discovery year.

Tap any cell for details ↓
Alkali Alkaline earth Transition Post-trans. Metalloid Non-metal Halogen Noble gas Lanthanide Actinide Unknown

Interactive Periodic Table

The periodic table of elements is one of science's greatest organisational achievements. Dmitri Mendeleev published the first systematic periodic table in 1869, arranging 63 known elements by atomic weight and predicting the existence of undiscovered ones - a remarkable feat of pattern recognition. Today, the table contains 118 confirmed elements, the most recent being Oganesson (element 118), officially named in 2016. Each element is uniquely defined by its atomic number, which equals the number of protons in its nucleus.

Relevance to Indian Science Education

The periodic table is a core component of the CBSE Class 10 and Class 12 chemistry syllabus, and understanding its structure - periods, groups, blocks (s, p, d, f), and trends in atomic radius, ionisation energy, and electronegativity - is essential for scoring well in board examinations. The NEET examination, which over 20 lakh students appear for annually to secure MBBS seats, includes a significant number of chemistry questions based on periodic trends. JEE Advanced also tests deep knowledge of element properties, electron configurations, and reactivity patterns.

India's Contribution to Element Discovery

India has a notable place in the history of chemistry. C.V. Raman's Nobel Prize-winning work in 1930 on light scattering (the Raman Effect) advanced molecular spectroscopy used in elemental analysis. More recently, Indian scientists at BARC (Bhabha Atomic Research Centre) contribute to nuclear physics research related to heavy elements. Element 113, Nihonium, was confirmed in 2015, and current research continues into elements beyond 118 through international collaborations including Indian institutions.

Periodic Table Questions

The periodic table currently contains 118 confirmed elements - from Hydrogen (atomic number 1) to Oganesson (atomic number 118). Elements 1–94 occur naturally on Earth; elements 95–118 are synthetic, produced in particle accelerators. The most recently named elements received official IUPAC names in 2016: Nihonium (Nh, 113), Moscovium (Mc, 115), Tennessine (Ts, 117) and Oganesson (Og, 118). Elements 119 and 120 are currently being synthesised in laboratories.

The periodic table was developed by Russian chemist Dmitri Mendeleev in 1869, who arranged the 63 known elements by increasing atomic weight and noticed recurring chemical properties at regular intervals. He famously left gaps for undiscovered elements and predicted their properties accurately. In 1913, Henry Moseley revised the table to arrange elements by atomic number (protons) instead of atomic weight, resolving several inconsistencies - this is the basis of the modern periodic table.

The 118 elements are categorised into: Alkali metals (Group 1) - highly reactive metals like sodium and potassium; Alkaline earth metals (Group 2) - calcium, magnesium; Transition metals (Groups 3–12) - iron, copper, gold, silver; Post-transition metals - aluminium, lead, tin; Metalloids - silicon, arsenic; Nonmetals - carbon, nitrogen, oxygen; Halogens (Group 17) - fluorine, chlorine; Noble gases (Group 18) - helium, neon, argon; and Lanthanides and Actinides - rare earth and radioactive elements.

Electron configuration describes how electrons are distributed in an atom's shells and subshells. It is written as a series of subshell notations, e.g., Carbon is 1s² 2s² 2p² (2 electrons in the first shell, 4 in the second). Electron configuration determines an element's chemical behaviour - elements in the same group share similar outer-shell configurations and similar properties. For CBSE and state board chemistry exams in India, electron configuration is a core topic in Class 11 Chemistry (Chapter 2: Structure of Atom).

For CBSE Class 11–12 and NEET preparation, focus on: Group 1 (Alkali metals) - Na, K, Li reactions with water; Group 2 (Alkaline earth metals) - Ca, Mg compounds; Group 13–17 (p-block) - Al, Si, P, S, Cl chemistry; d-block (transition metals) - Fe, Cu, Zn, Cr oxidation states and complex ions; Lanthanides - lanthanide contraction; and Radioactive elements - U, Th decay series. The periodic table is covered in Chapter 3 (Classification of Elements) of NCERT Class 11 Chemistry.