HEALTH, NUTRITION & FITNESS • FLUID INTAKE

Title: The Wonderful World of Water

(Hydration)

Grade(s): 6-7

Introduction: Water is our essence, our very lifeblood, the most important nutrient in our body. It makes up 70 percent of our muscles and 75 percent of our brains; oxygen is the only thing the body craves more than water. Yet every time we exhale, we lose it, as much as two cups a day. Water evaporates invisibly from the surface of our skin too, an additional two cups a day; and each time we urinate, we lose even more-probably as much as 2 pints in a 24-hour period. During the course of a regular day, a healthy adult can lose eight to ten cups of water, and that is before working out at the gym.

When we fail to replenish the losses, we set up a physiological chain reaction. Reading a “water shortage” (dehydration) message, hormones tell the kidneys to conserve water by urinating less; the urine passed is amber-colored (healthy water intake produces light-tinted urine). At a 3 percent loss of body weight, muscular endurance diminishes; at 4 percent, dizziness occurs, and physical labor capacity drops by as much as 30 percent; at 5 percent, mental concentration is reduced, drowsiness, impatience and headaches occur; at 6 percent, the heart rate increases and the body’s temperature regulation system starts to fail; at 7 percent, there is a good chance of collapse.

Learner Objective(s):

• The student will be able to explain the importance of proper body hydration.
• The student will be able to list the signals of dehydration in the body and ways to prevent it.
• The student will be able to demonstrate how electricity can split water into its two gases.

Florida Sunshine State Standards: Science: SC.A.1.3.1 Math: MA.B.3.3.1

Competency Based Curriculum: Science: M/J - III-1-A Math: M/J - III-2-A

Materials (Part A):

Petri Dish (one per 2 students)
Filter Paper
Vinegar
Rubbing Alcohol
Water
Soap
Forceps
Pencil
Radish seeds

Activity Procedure(s): Part A - Water Needed To Survive

1. Label (in pencil) the petri dish into four sections: water, vinegar, soap, and alcohol.
   
   
2. Wet the filter paper in the petri dish.
   
   
3. Place five water-soaked radish seeds on the section labeled “water”.
   
   
4. Using the forceps, rinse off-five vinegar-soaked seeds and place them on the section labeled “vinegar”.
   
   
5. Using the forceps, rinse off five soap-soaked seeds and place them on the section labeled “soap”.
   
   
6. Using the forceps, rinse off five alcohol-soaked seeds and place them on the section labeled “alcohol”.
   
   
7. Cover the seeds with a wet paper towel or filter paper.
   
   
8. Label the petri dish (name & date) and store it for a few days.
   
   
9. Following a few days, examine the seeds and record observations.

Materials Part B:

One 9-volt battery (per 2 students)
Two regular #2 pencils (remove eraser and metal part on ends)
Salt
Thin Cardboard
Electrical Wire
Small Drinking Glass
Water

Activity Procedure(s): Part B - Water Hydrolysis

1. Sharpen two pencils at both ends.
   
   
2. Cut the thin cardboard to fit over the small glass filled with warm water.
   
   
3. Push the two pencils into the cardboard, about an inch apart.
   
   
4. Dissolve a teaspoon of salt into the water and let it sit for a while.
   
   
5. Using one piece of the electrical wire, connect one end on the positive side of the battery and the other to the black graphite (lead of the pencil) at the top of the sharpened pencil. Do the same for the negative side connecting it to the second pencil top.
   
   
6. Place the other two ends of the pencil into the salt water.
   
   
7. Observe and record.

Student Assessment:

Allow student to answer critical thinking skills questions assigned by the teacher.

1. Why should divers be well-hydrated prior and between dives?
   
2. Suppose you had placed five dry seeds in a dry petri dish, what would have happened? Why?

Ask the student to report observations/results of each group of seeds of Part A Activities Procedures.

Ask the student to report observations of Part B Activities Procedures.

Activity Extension(s):

Electricity can be used to produce chemical changes. Encourage students to give examples of this phenomena (Physical Science).

People should drink 50-75% of their body weight in ounces. If an individual weighs 150 lbs., how many ounces of water should this person drink? Follow -up similar calculation with each student of the class (Math).

Allow students to read Hemingway’s The Old Man and The Sea and have them discuss excerpts where dehydration signals are described (Language Arts).

Home Learning Activity:

Students are to weigh themselves prior to high impact aerobic activity (i.e., running, biking) for an extended period of time. They are encouraged to weigh themselves after the activity.The weight findings are to be documented and accounted for.

Vocabulary: hydration, dehydration, hormones

References/Related Links:

http://www.naturodoc.com/WAATER.php3
http://www.healthcentral.com/mhc/top/
http://www.gulftel.com/~scubadoc/dehyd.htm