Classification of metals according to their chemical activity

The video explains the chemical activity of metals, classifying them into very active, less active, and inactive categories based on their reactivity with oxygen. Very active metals like sodium and potassium react quickly with air and are stored in kerosene. Less active metals such as aluminum, copper, and iron form rust over time and require protective coatings. Inactive metals like gold and silver are resistant to oxidation and are used in jewelry and protective coatings.

What are the three classifications of metals based on their chemical activity?

• Reactive, Semi-reactive, Non-reactive

• Active, Passive, Neutral

• Very active, Less active, Inactive

• Highly reactive, Moderately reactive, Non-reactive

Why are sodium and potassium stored in kerosene?

• To enhance their luster

• To prevent them from melting

• To stop them from reacting with oxygen and water vapor

• To make them more reactive

Which metals are known to form a rust layer when exposed to air for some days?

• Sodium and potassium

• Aluminum, copper, and iron

• Gold and silver

• Platinum and chromium

What is the primary reason for coating steel bridges with grease?

• To make them shiny

• To protect them from rust and corrosion

• To increase their weight

• To change their color

Why are metals like gold and silver used in making jewelry?

• They are heavier than other metals

• They are cheaper than other metals

• They are difficult to react with oxygen

• They are very reactive with oxygen