What is …

Big Ideas: Earth is a UNIQUE life-supporting planet within our solar system.

Big Ideas: Water is a limited natural resource that is ESSENTIAL to life.

Big Ideas: Water displays “COHESIVE” (sticky) characteristics.

Big Ideas: All MATTER is made of tiny particles called ATOMS.

It’s ESSENTIAL for RESPIRATION (breathing), of course. What is the most ABUNDANT atom on Earth? The OXYGEN atom! It’s ESSENTIAL for RESPIRATION (breathing), of course. References: http://sdsu-physics.org/ and http://wps.prenhall.com/

Earth’s crust Human body Some data for your viewing pleasure: Earth’s crust Human body CONCLUSIONS?? It looks like Oxygen takes the pie here … I mean … takes the cake. References: http://sdsu-physics.org/ and http://wps.prenhall.com/

HOW?? … might you ask. Hold your atoms … I’m getting to that! What is the most ABUNDANT atom in the UNIVERSE? The HYDROGEN atom! Hydrogen is the most abundant element in the UNIVERSE. Nine out of every 10 atoms in the universe are hydrogen atoms. That’s 90 percent, which equals three quarters of the MASS of the universe. It has the lowest density. Earth’s gravity can’t hold it easily. It escapes gravity and floats off into space! It is essential for life. It is present in nearly all the molecules in living things. HOW?? … might you ask. Hold your atoms … I’m getting to that!

Hydrogen also occurs in the stars and powers the universe. It’s a simple element. Its atoms contain 1 positively-charged proton and 1 negatively-charged electron. Do you remember the POSITIVE AND NEGATIVE poles when you studied MAGNETS? Do you remember the term ATTRACTION?

A molecule is when atoms are attracted and are BOUND together A molecule is when atoms are attracted and are BOUND together. They create a bond … like you and your best friend Sue … or Stu. Hydrogen combines with other elements to form molecules.

What is water? A water molecule combines 2 hydrogen atoms strongly bonded with 1 oxygen atom. Water molecules are called “polar” molecules because each water molecule has a positive end and a negative end.

Our planet is COVERED with oxygen and hydrogen atoms! Our bodies are mostly made of water. Our planet is covered mostly with water. 71% Water!! CONCLUSIONS?? Our planet is COVERED with oxygen and hydrogen atoms!

Water molecules are attracted to one another. The negative oxygen end of a water molecule is attracted to the positive hydrogen end of another water molecule forming a weak hydrogen bond between water molecules.

How many drops of water can you fit on a penny? Time for an experiment. How many drops of water can you fit on a penny? Take a look at this picture. MATERIALS: eye dropper – penny – paper towel – plastic cup with water Make a PREDICTION, or HYPOTHESIS, about how many drops of water will fit on the penny. . Place the penny on a paper towel. Use a dropper to drop drops of water onto the penny. Count and record the number of drops. Repeat the procedure using the following variation (don’t forget your HYPOTHESIS: -Heads side of the penny versus tails side Explain your results.

The molecules hold together. They are ATTRACTED The molecules hold together. They are ATTRACTED. This attraction is called “cohesion.” Because of cohesion, water molecules below the surface are equally attracted in all directions. The molecules on the surface are only attracted to the sides and down. This makes water act as if it has a “skin.” That’s why you can fill a glass of water, just above the brim. There is a skin-like surface of the water. This skin-like surface of water is called “surface tension.” Reference: Shlichting, Blackmer and Smith, Super Science Sourcebook, The Idea Factory, 1988.

Water makes life as we know it possible Water makes life as we know it possible. Every drop cycles CONTINUOUSLY through air, land, and sea, to be used by someone (or something) else “downstream.” Water covers 70% of Earth’s surface, but only 3% is fresh, and only a fraction of one percent supports all  life on land. Protect it. It is a LIMITED NATURAL RESOURCE. http://www.amnh.org/explore/science-topics/water-and-life-on-earth