Metals and Non-Metals — Study Notes

Overview

Metals and non-metals form a fundamental classification in chemistry that appears regularly in Railway Group D exams. This topic tests your understanding of the physical and chemical properties that distinguish these two classes of elements, their behavior in reactions, and basic extraction processes. Expect 2–4 questions covering property identification, reactivity comparisons, corrosion, and simple metallurgy concepts.

Understanding the reactivity series is crucial—it predicts how metals react with acids, water, and other metals. Questions often present a reaction scenario and ask you to identify the correct outcome or select the most reactive metal. Metallurgy basics, including extraction methods for common metals like iron, aluminum, and copper, also appear frequently. Master the correlation between a metal's position in the reactivity series and its extraction method.

The topic connects directly to everyday applications—corrosion prevention, alloy formation, and industrial metal production—making it practical and memorable for exam preparation.

Key Concepts

• **Physical properties of metals**: Metals are lustrous (shiny), malleable (can be hammered into sheets), ductile (can be drawn into wires), good conductors of heat and electricity, have high melting and boiling points (except mercury), and produce a ringing sound when struck (sonorous). Most metals are solid at room temperature; mercury is the only liquid metal.

• **Physical properties of non-metals**: Non-metals are generally dull in appearance, brittle (break easily when stressed), non-malleable, non-ductile, poor conductors of heat and electricity (except graphite, a form of carbon), and have relatively lower melting and boiling points. Many non-metals exist as gases at room temperature (oxygen, nitrogen, chlorine) or solids (sulfur, phosphorus); bromine is the only liquid non-metal.

• **Chemical properties of metals**: Metals lose electrons to form positive ions (cations). They react with oxygen to form metal oxides which are basic in nature. Metals react with water and acids to release hydrogen gas. More reactive metals displace less reactive metals from their salt solutions.

• **Chemical properties of non-metals**: Non-metals gain electrons to form negative ions (anions). They react with oxygen to form non-metal oxides which are acidic or neutral. Non-metals generally do not react with water or dilute acids (except in special cases).

• **Reactivity series**: Metals arranged in decreasing order of reactivity: Potassium > Sodium > Calcium > Magnesium > Aluminum > Zinc > Iron > Lead > Copper > Mercury > Silver > Gold. This series predicts reaction outcomes and extraction difficulty.