Periodic Classification of Elements Questions with Solutions

This topic covers the development of the periodic table (Dobereiner's triads, Newlands' law of octaves, Mendeleev's table and the modern periodic law), groups and periods, the properties of elements across the table, and noble gases, halogens and other important groups. Questions often ask who gave the modern periodic law (Henry Moseley, based on atomic number), which element is the most electronegative (fluorine), which metal is liquid at room temperature (mercury), and trends in atomic size and reactivity across periods and down groups. The modern periodic table has 18 groups and 7 periods. Practise the periodic table questions below, written in the style of the general awareness sections of exams such as SSC, banking, railways, CUET GAT, MAH CET and CLAT. Each question comes with a detailed explanation that adds related facts, so every question helps you revise more than one point.