Properties of Water Lab #1 - Water's Cohesive Tendency

While your kiddos might not understand what a hydrogen bond is, with a few simple materials, they can witness the attractive force at work as they explore water's cohesive tendency - or in 'kid speak', how drops of water like to stick together.


spray bottle


wax paper

drinking straw

Completing the Lab

  1. Provide each student with a piece of wax paper and a drinking straw.
  2. Using a spray bottle, spray a small amount of water onto the wax paper.
  3. Invite students to observe the water - i.e. the small separated drops of water on their wax paper.
  4. With the straw, encourage students to gently blow the water droplets around the wax paper.
  5. Over time, your students should notice that their small drops of water have become one large 'puddle'. This is the work of cohesion - the tendency of water molecules to stick together!