Pool Day – The Science of H2O

By Amanda Boyarshinov


Scientists learn by studying things in the world around them. Students get an EDGE on academics by discussing science, exploring materials, and using strong vocabulary. Encourage your child to take notes on their scientific discoveries and write down their observations throughout the entire summer.

By early elementary school, most children notice that some objects float on the water, while others sink to the bottom of the pool. Start off your pool day with a fun science review – sort your pool toys. One pile for the floaters (beach balls, floats, and foam balls) and one for the sinkers (aka dive sticks).  Explore with them in the water and discuss their materials, weight, and properties that may help them float or sink. Reinforce the concept of gravity, the attraction of an object to Earth and buoyancy, the force pushing an object to float.

Then dive into the science of H2O by creating your own pool day water toy – a flinker.

After School STEM Project: Make a Water Flinker

A flinker is a made up word used to describe an object that neither floats nor sinks. It doesn’t float or sink, it Flinks.

For this experiment and engineering design project you will need:

  1. An empty bottle
  2. Waterproof tape
  3. Other recyclables such as rubber bands, corks, sponges, or plastic lids.
  4. A tub of water or pool

Directions to make a flinker:

  1. Explain the idea of a flinker.  To be a successful bottle flinker, no part of the bottle can touch the surface of the water, nor the bottom of the container for 5 seconds.
  2. Using the empty water bottle as the base, design and build a flinker that will neither float nor sink in the pool.  Hint – try filling the bottle part-way with water.
  3. Test the design. If the design sinks or floats, make modifications to the original design.
  4. Continue testing and making adjustments until a successful flinker has been made.

Educators Tip: Extend science vocabulary by using the words, gravity and buoyancy during your science exploration.

Advanced options: Encourage children to weigh their flinker prior to each test and record weight and the results of the test.

10 Fun Facts about Water to Share with Others on Pool Day

  1. 3/4th of the Earth is covered with water.
  2.  Only a very small portion of the water on Earth is fresh water, but most is salt water.
  3. We need water to survive.
  4. We use water to drink, keep our bodies clean, and to grow food.
  5. Water makes up more than half of the human body.
  6. Water naturally takes the form of a solid, liquid, and gas.  When water is in gas form, it is called water vapor.
  7. Water is also referred to as H2O. This means that the water molecule contains two Hydrogen and one oxygen atoms.
  8. People can use water to make electricity.
  9. There is a limited amount of water available. It is important to reduce water consumption whenever possible.
  10. Water cycles through stages of evaporation, condensation, precipitation and collection. This is called the water cycle.