Do Now 1.Define the term independent variable. 2.Define theterm dependent variable Design a mini experiment and identify your independent and dependent variables.

Independent Variable: Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs when the shell develops a nasty slime and gives off a horrible odor. His friend Patrick tells him that rubbing seaweed on the shell is the perfect cure; Sponge Bob decides to test this cure by rubbing Gary with seaweed for 1 week. After a week of treatment, the slime is gone and Gary’s shell smells better. The independent variable is…

Independent Variable: THE SEAWEED CURE

Independent Variable: The variable controlled by the experimenter

Dependent Variable A scientist conducted an experiment to determine how the amount of salt in a body of water affects the number of plants that can live in the water. In this experiment the dependent variable is…

Dependent Variable NUMBERS OF THE PLANTS IN THE WATER

Dependent Variable the variable measured by the experimenter

Issues and Physical Science: Water Read Page C-3 in your textbook

Can you taste the difference? BACKGROUND INFORMATION: − Millions of Americans drink bottled water instead of, or in addition to, their local tap water. − Sales have skyrocketed in the past 20 years, to more than $10 billion in 2006.

Can you taste the difference? Why do people drink bottled water?

Can you taste the difference? It's hard to argue about taste and convenience, since these are personal preferences. BUT… a study released in 1999 shows that despite retail prices of up to 10,000 times the price of tap water, bottled water may be no safer-maybe even less safe-than tap water.

Can you taste the difference? The major difference between some bottled waters and tap water is that tap water has been chlorinated, whereas bottled water often is not. Until 1993, such terms as "mineral,” spring," "artesian,” "distilled," and "purified," were used on labels without clear standards

Can you taste the difference? These terms could be used if only 10% of the water came from that source. Many people buying bottled water with pictures of high mountain lakes on the label were dismayed to find that those bottles contained mostly tap water!

Can you taste the difference? Distilled water is produced by boiling It so that It forms vapor. Minerals, called dissolved solids, and most other contaminants do not vaporize and are left behind. The vapor Is then cooled to turn it back into liquid water.

Distilled Water Continued… Although this process produces very pure water, the large amounts of energy required to vaporize it make it very expensive. Distilled water is useful for steam irons, aquariums, and plant watering among other everyday uses.

Can you taste the difference? Bottled water is a food product regulated by the U.S. Food and Drug Administration (FDA), and tap water is a utility regulated by the U.S. Environmental Protection Agency (EPA).

Can you taste the difference? Tap water must be tested for harmful bacteria more than 100 times per month, while bottled water plants are required to test only once a week. The standards governing nearly 200 inorganic and organic chemicals are less strict for bottled water. And states in general have far fewer staff assigned to routinely test bottled water than tap water.

Also, in most communities, fluoride ions are added to the tap water to reduce tooth decay in children. Children who drink mainly bottled water do not get this fluoride, and if it is not supplied by another source (e.g. dentists or fluoride toothpaste), they are at risk for increased tooth decay

Title 30:Title of Lesson Date: White space: How do you decided to drink bottle or tap water? Summary of Introduction: Challenge: Key Words: Dissolved solids, Distilled water, spring water Procedure: I understand Materials: List and check off Data: Create the two data charts in your notebook. Notes to myself for tomorrow:

EXIT TICKET Rate yourself and your partners on lab participation.