1. 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.

2. 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

3. 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

4. Title: Water Pollution
Activity 34
Title: Water Pollution

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

6. 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.

7. 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

8. 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.

9. 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.

10. 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.

11. 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