Properties of Water School/program name Date

Background Information (for facilitator) Cohesion: Water is attracted to water. Adhesion: Water is attracted to other substances. Adhesion and cohesion are water properties that affect every water molecule on earth and also the interaction of water molecules with molecules of other substances. Essentially, cohesion and adhesion are the "stickiness" that water molecules have for each other and for other substances. Water drops are composed of water molecules that like to stick together, which explains why water falls from the sky as raindrops rather than individual molecules. Rain therefore is an example of the property of cohesion. When one corner of a piece of paper towel is dipped into a glass of water the water will climb the fibers of the paper. The water molecules are attracted to the molecules of the fabric with greater force than gravity and therefore are able to climb up the paper. Therefore adhesion is when water molecules are attracted to another surface. Surface tension is caused by the attraction of the particles at the surface layer by the quantity of the liquid. For water, surface tension happens when a water molecule is surrounded on all sides by other water molecules, which creates a sphere or ball. In the case of surface tension, cohesion is affected by the volume of water at the surface layer resulting elastic like force. The helps to explain why some small insects, like a water strider, can walk on water. In the case of a water strider the weight of the insect is less than the force necessary to penetrate the surface of the water. Buoyancy is an upward force exerted that opposes the weight of a fully or partially immersed object. If the upward force exerted is equal to or greater than the density of the immersed object the object is deemed buoyant. This is the principle that allows large cruise ships and fishing vessels to remain afloat even though individual pieces of the vessel would sink if not part of the whole.

Agenda Opening (30 minutes) Setting the Stage (20 minutes) Activity: Camp Song, “Little Water Molecule” (10 minutes) Cyber Investigation: Just Dunk It (15 minutes) Setting the Stage (15 minutes) Activity: Cohesion and Surface Tension of Water (60 minutes) Break (15 minutes) Cyber Investigation: Sea Trials (15 minutes) Lunch (30 minutes) Recess: Water Sponge Relay (30 minutes) STEM-tastic Careers (30 minutes) Mind Snacks (15 minutes) Engineering Challenge: Boat Building Challenge (75 minutes) STEM Camp Notebook Reflection (20 minutes) Wrap Up (10 minutes) Dive Into Digital Project (60 minutes)

Learning Objectives To explain the basic chemistry of water To investigate properties of water including cohesion and adhesion

Today’s Vocabulary Surface Tension Molecule Volume

Setting the Stage

Water Properties Quiz

Activity: Camp Song “Little Water Molecule”

Cyber Investigation: Just Dunk It Exploration: Just Dunk It

Setting the Stage Reading Passage – Getting to know Properties of Water

Activity: Cohesion and Surface Tension of Water Hands-On Lab: Cohesion and Surface Tension of Water

Cyber Investigation: Sea Trials

STEMtastic Careers aquacultural manager aquarist, Hydrologist, water and liquid waste treatment plant operator chemical technician chemist ship and boat captain computer software engineer Economist, remote sensing scientist biochemical engineer hydroelectric plant technician materials scientist

Mind Snacks

Engineering Challenge: Boat Building Engineering Project: Boat Building Challenge

Notebook Reflection What have you learned about the properties of water? How do the properties of water impact living organisms? What is your favorite water activity? How does it relate to the properties of water? Which careers you examined today most intrigue you and why are you interested in them?

Wrap Up

Water Properties Quiz

Exploration: Waters of the Earth