Liquid nitrogen demonstrations

In this activity, students observe the teacher demonstrating changes in the properties of common substances when cooled with liquid nitrogen.

Rights: Sascha Meinrath

Liquid nitrogen

Liquid nitrogen is a common laboratory coolant. With a boiling point of -196°C, it is cold enough to instantly freeze moist air in its vicinity. The ‘smoke’ is made up of tiny ice crystals.

By the end of this activity, students should be able to:

• realise that the properties of materials are often temperature-sensitive
• recognise that the boiling point of liquid nitrogen is extremely low
• show awareness of the potential hazards that exposure to liquid nitrogen can invoke
• explain in simple terms the reason behind the main changes occurring in each of the demonstrations.

Download the Word file (see link below) for:

• introduction/background notes
• instructions on what you need and what to do
• discussion questions
• ideas for extending your students.