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