Food Preservation

October 30th -

Today in class we are discussing (and seeing a demonstration of) radioactivity. Common uses of radiation include medical and energy needs - we are all familiar with x-rays and have at least some sense of the nuclear power produced in the state of Texas. However, we are not as familiar with the use of radiation when considering our food supply. In many countries around the world (where refrigeration is not available in homes or stores), irradiating food is a primary method of food preservation. It is not at all unusual to go to a market, pick up a carton (or jug) of milk from a shelf at room temperature and buy it to drink later - it does not need to be kept cold because it will not spoil. This is one advantage to irradiating food. Use the link below to read a document from the United States' FDA (Food and Drug Administration). Then answer the question below.

http://www.fda.gov/opacom/catalog/irradbro.html

Citing information from the brochure (that means you have to read it) give 2 reasons why you:

1. would feel comfortable buying and eating irradiated foods.

2. would not feel comfortable buying and eating irradiated foods.

Please note, there is not a "choose one of these" option - answer both questions!

This is due by Friday. See you in class.

ms. h

Tests and their Importance

For most of us, a test is a pain in the neck (or some other place) but a necessary part of schooling. While I do not place a great deal of emphasis on test grades, our school's grading policy does. I can certainly understand the idea that "you don't like chemistry" or "you don't get it". And trust me, I don't take it personally - it's something you are required to take and something that I understand pretty well so I'm trying to help you understand as well.

Imagine my surprise when I graded the first tests we took (now almost 2 weeks ago) that dealt only with chemistry concepts. The average of the 3 classes was somewhere around 67 - not a grade which represents the collective intelligence of you folks.

Someone in each class (no names) asked if I would give "a curve" or "extra credit". The answer is and will always be "no". I want you to think about something here - and to give me some feedback (that means leave me a comment - this is how you earn bonus points for your grade - by leaving a thoughtful comment). How would you feel if you knew that your doctor, your dentist, your lawyer, your surgeon, your pilot (you get the idea) got their professional license by getting extra credit points or a curve or made a really neat poster instead of passing their courses because they studied and knew what they were doing?


Just something to consider....

Hope you studied this time!

ms. h

New Assignment

Check out the website below. From the website, you need to choose one element and then complete the assignment sheet from class.

http://www.webelements.com/

Be sure to post the element that you selected.

Have a great weekend!!

ms. h

Answers to last week's questions

1. point at which liquid changes to solid - freezing point

2. point at which solid changes to liquid - melting point

3. change from solid to gas (without becoming a liquid)- sublimation; examples include dry ice, solid iodine and (in the reverse - gas to solid without becoming a liquid) snow

Lab Experiment

What was the most difficult part of last week's lab?