Make A Simple Thermometer Follow FizzicsEd 150 Science Experiments: Comments 0 You will need: One Screw top container One Clear Straw Something to make a hole with eg. nail or hand drill Food Colouring Hot water bath, ice bath and hair dryer (Optional) Moulding clay and a permanent marker Balloons or Water Balloons (Options available also Blu-Tak or Plasticine) Container Scissors Straw Adult Help Written by Fizzics Education. Reviewed by Ben Newsome CF. Cite this experiment Copyright Notice Instruction Video Instruction 1 Carefully, and with the help of an adult, bore a hole into the middle of the containers’ lid. Make sure that the hole made is only slightly bigger than the diameter of your straw. SAFETY: If children are to do this, make sure that the hand drills are not electrically powered. Alternatively, hand drill the lids prior to children commencing the experiment or use balloons instead of a plastic lid. ALTERNATE VERSION: Use a bottle that already has a small opening (e.g. soft drink bottle) or Use balloon or water balloon. 2 Thread the straw through the hole and seal the joint with the moulding clay (Important: Roll the moulding clay around the edge of the lid making sure of a good airtight seal. You can also use a balloon with a hole in it to make a tight seal around the straw and bottle opening. 3 Fill your container to the brim with water and add in a couple of drops of food colouring. 4 Gently blow into the straw – blowing hard may cause the water to rush up into your face! 5 Blowing into the straw forces air into an enclosed space, thereby increasing the pressure within the container. If your seals are airtight, you will find that water will rise up the straw once you stop blowing. This may require some trouble shooting! 6 Mark the water level on the straw with the marker – this mark identifies where the water will be when at room temperature. 7 Now hold the container between your hands, thereby gently heating the water inside. Alternatively you can use the hot water bath or even a hairdryer. If all has gone well you will find that the water will have travelled up the straw. SAFETY: Using electrical appliances near water can be dangerous, please have an adult demonstrate this experiment. 8 Now try placing the home made thermometer into an ice bath, what will happen to the water? 9 School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too! 10 Get the Unit of Work on Heat Energy here! What actually is heat? How does heat move through different materials? How does heat change the properties of materials and more! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more 11 Online courses for teachers & parents – Help students learn how science really works Why Does This Happen? The Science of Thermal Expansion The basic principle of a thermometer is thermal expansion. When liquids are heated, their molecules gain kinetic energy and begin to move more vigorously. As they vibrate and collide, they push further apart, causing the liquid to take up more space and expand. In your DIY thermometer, the expanding water has nowhere to go but up the straw! This same principle helps scientists to model the movement of ocean currents around the world, as warmer, less dense water expands and moves differently than colder, denser water. This is exactly how a traditional mercury thermometer works. Mercury is used because it remains a liquid at temperatures as low as -39°C and expands at a very predictable, rapid rate when heated. Additionally, its convex meniscus (the way the top of the liquid curves upwards) allows for very accurate temperature readings against a scale. Variables to test Find out more on variables here. Sensitivity Can you make a thermometer with a wider straw? Does a wider straw make the thermometer more or less sensitive to small changes in temperature? Liquid Properties What happens if you change the liquid to vegetable oil or methylated spirits? Different liquids have different coefficients of expansion, meaning some will rise much faster than others. Safety Note: Do not expose methylated spirits to any heat source other than direct sunlight. Insulation What happens if you wrap the bottle in Aluminium foil? Does it take longer for the water inside to react to the outside temperature? ✅ Reviewed: April 5, 2026 APA 7 Citation: Fizzics Education. (2018). Make a simple thermometer. https://www.fizzicseducation.com.au/150-science-experiments/kitchen-chemistry-experiments/make-a-simple-thermometer/ Copy APA Citation Reviewer This resource was last reviewed for scientific accuracy on April 5, 2026. Ben Newsome CF is the recipient of the 2023 UTS Chancellor’s Award for Excellence and a Churchill Fellow. He is a global leader in science communication and the founder of Fizzics Education. Learn more!! From colour changes to slimy science, we’ve got your kitchen chemistry covered! Get in touch with FizzicsEd to find out how we can work with your class. Hot & Cold Workshop Years 1 to 6 Maximum 30 students School workshop (NSW & VIC) 60 or 90 minutes Online Class Available Read More Enquire Now Sunprint Kit $16.45 excl. GST View Details Add to Cart Trustpilot STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
Carefully, and with the help of an adult, bore a hole into the middle of the containers’ lid. Make sure that the hole made is only slightly bigger than the diameter of your straw. SAFETY: If children are to do this, make sure that the hand drills are not electrically powered. Alternatively, hand drill the lids prior to children commencing the experiment or use balloons instead of a plastic lid. ALTERNATE VERSION: Use a bottle that already has a small opening (e.g. soft drink bottle) or Use balloon or water balloon.
Thread the straw through the hole and seal the joint with the moulding clay (Important: Roll the moulding clay around the edge of the lid making sure of a good airtight seal. You can also use a balloon with a hole in it to make a tight seal around the straw and bottle opening.
Blowing into the straw forces air into an enclosed space, thereby increasing the pressure within the container. If your seals are airtight, you will find that water will rise up the straw once you stop blowing. This may require some trouble shooting!
Mark the water level on the straw with the marker – this mark identifies where the water will be when at room temperature.
Now hold the container between your hands, thereby gently heating the water inside. Alternatively you can use the hot water bath or even a hairdryer. If all has gone well you will find that the water will have travelled up the straw. SAFETY: Using electrical appliances near water can be dangerous, please have an adult demonstrate this experiment.
School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too!
Get the Unit of Work on Heat Energy here! What actually is heat? How does heat move through different materials? How does heat change the properties of materials and more! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more
From colour changes to slimy science, we’ve got your kitchen chemistry covered! Get in touch with FizzicsEd to find out how we can work with your class.
Hot & Cold Workshop Years 1 to 6 Maximum 30 students School workshop (NSW & VIC) 60 or 90 minutes Online Class Available Read More Enquire Now
STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now
Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.
Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
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