PH Questions a. What do the formulas, arrow, and plus signs in a chemical equation tell you? The formulas tell you the elements and compounds involved in the reaction, the arrow means “yields” and points to the products, and the plus signs indicate two or more reactants or products b. How are reactants and products treated the same in a chemical reaction? How are they treated differently? Both reactants and products are written as formulas. Reactants are placed to the left of the reaction arrow, whereas products are placed to the right side of the reaction arrow.

a. How does the idea of atoms explain the principle of conservation of matter? In a chemical reaction, the number of atoms stays the same. This shows that matter is not created or destroyed during a chemical reaction. b. If the total mass of the products of a reaction is 250 g, what was the total mass of the reactants? 250 g

Balance the following equations: 4. __Fe2O3 + __C → __Fe + __CO2 Reactants: 4Fe, 6O, 3C Products: 4Fe, 6O, 3C 5. __SO2 + __O2 → __ SO3 2SO2 + O2 → 2SO3 Reactants: 2S, 6O Products: 2S, 6O 4 2 3 2 3 2 2

Title: Water Pollution Activity 34 Title: Water Pollution

Read C-21 Problem: What are some sources and types of water pollution? Hypothesis/Initial Thoughts:

What do you think of when you hear the term water contamination? Caused by various substances in the water. Could the contamination be dangerous to people’s health? Water-borne disease: a disease carried by water.

Read pgs. C-22 to C-27 Answer the stopping to think questions on paper. Fill in the blanks on the concept map as you read Begin analysis questions 1-4 Answer the conclusion question

Stopping to Think 1 What are the main types of biological contamination, and what are their sources? Human sewage containing cholera (not common today) Animal waste containing E. coli or Cryptosporidium from farms, pets, and meatpacking plants. Giardia can be found living naturally in rivers. The waste in water can contaminate food sources or enter the water supply in storm water.

Stopping to Think 2 What are some of the ways chemical contamination can get into the water supply? Fertilizers and chemicals used to kill weeds and pests on farms and lawns, gas, oil. Antifreeze from vehicles, copper from industry and copper water pipes, and acid and metals from mining waste.

Stopping to Think 3 What is it about water that makes water contamination such a big concern? Water travels easily and is hard to contain. Water is everywhere in the environment. Water is widely used and necessary for life.

Concept Map Water Pollution Storm Sewers Direct Water Pollution enters water by can be categorized as Direct Water Pollution Oil, gasoline, antifreeze Chemical Contamination Biological Contamination can be Lakes/rivers can be produced by may contain Fertilizer Vehicles can be Animal droppings (pets or wild can be Giardia produced by Acids Heavy metals Farms, Gardens Human sewage Animal waste from farms produced by contain Mines such as Bacteria contains contains contains Copper Lead E. coli Cryptosporidium Bacteria that causes Cholera released by released by can contaminate Corroded Water Pipes Vegetables and Crops