WATER SOFTENERS

IN THIS LESSON YOU WILL:

FIND OUT HOW A WATER SOFTENER WORKS

RESOURCES:

INTERNET SITES:

HTTP://WWW.THEWATERSITE.COM/HOW_THEY_WORK_WATER_SOFTENERS.HTM

LESSON 10: WATER SOFTENERS

FACTORS OF SCIENTIFIC LITERACY AND FOUNDATIONAL OBJECTIVES, LEARNING OBJECTIVES, SCIENCE 10 BIBLIOGRAPHY

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HOW DO WATER SOFTENERS WORK?

IF YOUR WATER SUPPLY GIVES YOU HARD WATER THEN YOU MAY WANT TO CONSIDER THE PURCHASE OF A WATER SOFTENER. A WATER SOFTENER IN YOUR HOME WILL CHANGE YOUR HARD WATER INTO SOFT WATER.

DO YOU REMEMBER WHAT SUBSTANCES MAKE WATER HARD?

AS YOU SHOULD KNOW, HARD WATER IS CAUSED BY THE DISSOLVED MINERALS: MAGNESIUM AND CALCIUM. SOFT WATER DOES NOT CONTAIN SIGNIFICANT AMOUNT OF THESE DISSOLVED MINERALS. SO, A WATER SOFTENER WILL HAVE TO SOMEHOW REMOVE THE MAGNESIUM AND CALCIUM IONS FROM THE WATER AND THEREBY LEAVE YOU WITH SOFT WATER.

ACTIVITY

FIND OUT HOW A WATER SOFTENER WORKS. GO!

ONCE YOU THINK YOU BASICALLY KNOW HOW A WATER SOFTENER WORKS, ANSWER THESE QUESTIONS. SOMETIMES THE COMPUTER CAN BE PRETTY PICKY IN THE WORDS THAT IT WILL ACCEPT AS CORRECT ANSWERS. DO YOUR BEST. SOMETIMES THE COMPUTER WILL REMARK THAT YOUR ANSWER IS WRONG BECAUSE YOUR ANSWER IS MISSING A KEY WORD FOR WHICH IT IS LOOKING. DON'T LET THIS BOTHER YOU. READ THROUGH THE COMPUTER'S EXPLANATION AND JUDGE FOR YOURSELF IF YOU KNOW HOW A WATER SOFTENER WORKS.

ANSWER THESE QUESTIONS:

1. IN A WATER SOFTENER, WHAT HAPPENS TO THE CALCIUM AND MAGNESIUM IONS?

2. THE PROCESS USED IN MANY WATER SOFTENERS THAT CHANGES THE HARD WATER INTO SOFT WATER IS KNOWN AS

3. A WATER SOFTENER HAS AN IMPORTANT COMPONENT CALLED THE MINERAL TANK. THIS TANK IS FILLED WITH SMALL BEADS MADE OF A MATERIAL SIMILAR TO A HARD PLASTIC OR STYROFOAM. OFTEN THIS MATERIAL IS RESIN OR ZEOLITE. WHAT CHARGE DO THESE BEADS CARRY?

4. WHY DO THE CALCIUM AND MAGNESIUM IONS CLING TO THE SMALL BEADS IN THE MINERAL TANK?

5. AFTER A WHILE THE BEADS IN THE MINERAL TANK WILL BE FULL OF CALCIUM AND MAGNESIUM IONS. THIS WILL SIGNAL THE WATER SOFTENER TO GO INTO A REGENERATING CYCLE THAT WILL CLEAN THE CALCIUM AND MAGNESIUM IONS OFF THE BEADS. HOW MANY PHASES ARE THERE IN THIS REGENERATING CYCLE?

HOW DID YOU DO ON THESE QUESTIONS? DID YOU GET MOST OF THEM CORRECT?

IF YOU STILL DON'T KNOW HOW A WATER SOFTENER WORKS, GO BACK TO THE WEBSITE ON WATER SOFTENERS AND READ THE INFORMATION THERE SLOWLY AND CAREFULLY. READING OUT LOUD MAY HELP YOU! THEN RETRY THE 5 QUESTIONS AGAIN.

ASSIGNMENT

WRITE A SUMMARY OF HOW A WATER SOFTENER WORKS. DO YOUR SUMMARY IN STEP FORMAT.

EXAMPLE:

STEP 1: HARD WATER ENTERS THE WATER SOFTENER
STEP 2: ~~~~~~~~~~
STEP 3: ~~~~~~~~~~

USE AS MANY STEPS AS IS NEEDED.

ASSESSMENT

YOU WILL EXCHANGE YOUR SUMMARY WITH ANOTHER STUDENT. EVALUATE YOUR CLASSMATE'S SUMMARY BASED ON THESE CRITERIA:

PRESENTATION (5)
ACCURACY (5)
COMPLETENESS (5)

YOU MAY USE THE WEB PAGE ITSELF AS A REFERENCE WHEN YOU MARK THIS STUDENT'S WORK OR YOU CAN SEE A SAMPLE SUMMARY.

TOTAL POSSIBLE SCORE = 15 MARKS

WRITE COMMENTS TO THIS STUDENT INDICATING TO THEM THE REASON(S) FOR A LESS THAN PERFECT SCORE OR IF THE SITUATION WARRANTS, INDICATE TO THEM THAT THEY DID A WONDERFUL JOB ON THE ASSIGNMENT!