Kitchen-Table Experiments

Grades 2-5About 60 minutes a week

The backyard engineer's habit is the fair test: change one thing, keep everything else the same, measure, and do it again. Every experiment below uses things already in the kitchen and ends with a result he found himself.

What you need

  • Cups, a pot, zip bags, ice and a freezer
  • Salt, sugar, sand, baking soda, vinegar, steel wool or an iron nail
  • Black and white paper, a thermometer, a kitchen scale
  • Balloons, toy cars, a board for a ramp, string and a washer
  • A few rocks, a steel spoon and a penny

What done looks like

  • He names the one variable before he touches anything.
  • His notebook has a prediction, a table of three runs and a conclusion.
  • He tells a physical change from a chemical one with evidence.
  • Another person repeated his experiment from his write-up alone.

What to do, grade by grade

  • Grade 2: pluck a stretched rubber band and change pitch and loudness on purpose.
  • Grade 3: ice melting in cups of warm vs cold water; sand and salt separated with water; salt water evaporated to get the salt back; thermometers under black and white paper in the sun; water cycle in a zip bag taped to a window; scratch-test rocks; a pendulum or rolling ball to predict the next swing.
  • Grade 4: weigh a flat vs full balloon; toy cars colliding from different ramp heights; freeze a full, capped plastic bottle of water and see it bulge or split; one variable, three runs each.
  • Grade 5: baking soda and vinegar weighed before and after in a sealed bag; a nail rusting over a week, wet vs dry; separate a trail mix and weigh the parts; identify white powders by tests; design and defend his own test; a write-up someone else can repeat.

How to teach it

  1. Before starting, he says what he thinks will happen and why, and writes it down.
  2. Ask: "What is the one thing we are changing? What are we measuring? What stays the same?"
  3. Run it three times. If the results disagree, that is information, not failure.
  4. Weigh before and after whenever something changes form. The weight stays the same in a closed bag: matter is not lost.
  5. A new substance shows itself by bubbles of gas, a new color, heat, or a solid that was not there. Rust is a new substance; melted ice is not.
  6. The conclusion says what the data shows and one thing it does not show.
  7. Test the write-up: hand it to someone else and watch them repeat it without asking questions.

Safety: Safety glasses for anything that fizzes. Never taste. An adult handles hot water and the freezer bottle. Wash hands after rocks and rust.

Curriculum goals this sheet covers (27)

In the words of the grade-by-grade guide.

  • Show that sound comes from something vibrating, and change a sound's pitch or loudness on purpose.
  • Predict where an object will go next from a pattern in how it has been moving.
  • Measures a repeating pattern in an object's motion and uses that pattern to predict what it will do next
  • Observes and records how heat moves from a warmer material into a colder one, changing ice from solid to liquid
  • Combines materials into a mixture and separates them again using a physical property only one of them has
  • Shows that a dissolved solid is still present in a solution and comes back when the water evaporates
  • Measures temperature to show that dark surfaces absorb more light energy and turn it into heat than light surfaces do
  • Models the water cycle by showing water evaporating, condensing and falling again in a closed container
  • Tests and records hardness as a physical property of rocks and connects it to how fast rock wears away
  • Design and conduct an investigation with one variable you control and one you measure, and run it more than once.
  • State a conclusion the data supports, and say plainly what the data does not show.
  • Proves that a gas is matter by showing that air takes up space and has weight
  • Asks questions and predicts what happens to energy when two objects collide (NGSS 4-PS3-3; Texas TEKS 4.8(A))
  • Uses evidence to construct an explanation relating the speed of an object to the energy of that object (NGSS 4-PS3-1)
  • Models and describes slow changes to Earth's surface caused by weathering from ice (Texas TEKS 4.10(B); NGSS 4-ESS2-1)
  • Determines the physical properties of rocks and describes the processes that form and change rock over time (Texas TEKS 4.11(C); NGSS 4-ESS2-1)
  • Design an investigation of her own, including what to control and what to measure, and defend the design out loud.
  • Demonstrate that matter is conserved when a substance changes form or dissolves.
  • Write up an investigation clearly enough that another person could repeat it without asking questions.
  • NGSS 5-PS1-4: conduct an investigation to determine whether the mixing of two or more substances results in new substances
  • NGSS 5-PS1-4: investigate whether combining substances makes a new substance, using a change that takes days instead of seconds
  • NGSS 5-PS1-4: determine whether mixing two substances results in a new substance with different properties
  • NGSS 5-PS1-4: identify a chemical change by evidence that a new substance formed, and test a condition that changes it
  • TEKS 5.6(B): demonstrate and explain that some mixtures maintain the physical properties of their substances
  • TEKS 5.6(B) and 5.6(C): separate a mixture using physical properties and show that matter is conserved in a solution
  • NGSS 5-PS1-3: make observations and measurements to identify materials based on their properties, and TEKS 5.6(B) on mixtures keeping their parts
  • NGSS 5-PS1-3: make observations and measurements to identify materials based on their properties

Goals covered: Show that sound comes from something vibrating, and change a sound's pitch or loudness on purpose.Predict where an object will go next from a pattern in how it has been moving.Measures a repeating pattern in an object's motion and uses that pattern to predict what it will do nextObserves and records how heat moves from a warmer material into a colder one, changing ice from solid to liquidCombines materials into a mixture and separates them again using a physical property only one of them hasShows that a dissolved solid is still present in a solution and comes back when the water evaporatesMeasures temperature to show that dark surfaces absorb more light energy and turn it into heat than light surfaces doModels the water cycle by showing water evaporating, condensing and falling again in a closed containerTests and records hardness as a physical property of rocks and connects it to how fast rock wears awayDesign and conduct an investigation with one variable you control and one you measure, and run it more than once.State a conclusion the data supports, and say plainly what the data does not show.Proves that a gas is matter by showing that air takes up space and has weightAsks questions and predicts what happens to energy when two objects collide (NGSS 4-PS3-3; Texas TEKS 4.8(A))Uses evidence to construct an explanation relating the speed of an object to the energy of that object (NGSS 4-PS3-1)Models and describes slow changes to Earth's surface caused by weathering from ice (Texas TEKS 4.10(B); NGSS 4-ESS2-1)Determines the physical properties of rocks and describes the processes that form and change rock over time (Texas TEKS 4.11(C); NGSS 4-ESS2-1)Design an investigation of her own, including what to control and what to measure, and defend the design out loud.Demonstrate that matter is conserved when a substance changes form or dissolves.Write up an investigation clearly enough that another person could repeat it without asking questions.NGSS 5-PS1-4: conduct an investigation to determine whether the mixing of two or more substances results in new substancesNGSS 5-PS1-4: investigate whether combining substances makes a new substance, using a change that takes days instead of secondsNGSS 5-PS1-4: determine whether mixing two substances results in a new substance with different propertiesNGSS 5-PS1-4: identify a chemical change by evidence that a new substance formed, and test a condition that changes itTEKS 5.6(B): demonstrate and explain that some mixtures maintain the physical properties of their substancesTEKS 5.6(B) and 5.6(C): separate a mixture using physical properties and show that matter is conserved in a solutionNGSS 5-PS1-3: make observations and measurements to identify materials based on their properties, and TEKS 5.6(B) on mixtures keeping their partsNGSS 5-PS1-3: make observations and measurements to identify materials based on their properties

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