Metals and Non-metals | Class 10 Science Notes

3.2 CHEMICAL PROPERTIES OF METALS

This section explores the chemical behavior of metals, focusing on their reactions with oxygen, water, acids, and salt solutions. Metals react with oxygen to form metal oxides, which are generally basic in nature. For example, copper reacts with oxygen to form black copper(II) oxide, and aluminium forms aluminium oxide. Some metal oxides like aluminium oxide and zinc oxide are amphoteric, reacting with both acids and bases. Metals vary in their reactivity with oxygen; highly reactive metals like sodium and potassium react vigorously, sometimes catching fire, and are stored under kerosene to prevent accidental ignition. Metals like iron, zinc, and aluminium form protective oxide layers that prevent further oxidation. The section also discusses the reaction of metals with water: highly reactive metals like potassium and sodium react violently with cold water producing metal hydroxides and hydrogen gas, while others react only with steam or hot water. Metals react with dilute acids to produce salts and hydrogen gas; the rate of reaction varies with metal reactivity. Displacement reactions occur when a more reactive metal displaces a less reactive metal from its salt solution. These chemical reactions help establish the reactivity series of metals, a list arranged in decreasing order of reactivity. The section includes several activities demonstrating these reactions and their observations.

📊 Diagram: Figure 3.3 Action of steam on a metal; Figure 3.4 Reaction of metals with salt solutions; Table on page 9 (13×3)

🧪 Activity: Activities 3.8 to 3.12 involve burning metals in air, reacting metals with water and acids, and displacement reactions with metal salt solutions.

🔗 Connection: Leads to understanding how metals and non-metals react chemically and the formation of ionic compounds.

Table on page 9 (13×3)