October 14

Mold

In fifth grade we performed an experiment to determine the best environment for mold growth.  For Mrs. Pannek’s class, I purchased inexpensive white bread from the grocery store.  We dropped water on the bread slices and sealed each slice in a Ziploc bag.  Then each group placed the bread on the counter, in a cabinet and in the refrigerator.  Each student formed his/her hypothesis and then we waited and waited.  Mrs. McElroy’s class did the same experiment, but I changed a variable and purchased white bread from Harvest Bread Company.  After a month, there isn’t any evidence of mold on the bread in Mrs. Pannek’s class.  It took almost three weeks, but the bread from the Harvest Bread Company began to mold in the cabinet and on the counter.  The bread in the refrigerator still has no mold growth.  We had a discussion about preservatives and discovered that calcium propionate was added to the white bread from Kroger’s to prevent mold growth.

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White Bread from Kroger

White bread from Harvest Bread Company

White Bread from Harvest Bread Company

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October 7

Texture

We use our sense of touch to determine an object’s texture.  Scientists use texture to classify and describe objects.  The following work was done in Pre-First.

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October 7

Daraja

We were so blessed to have the Daraja Choir visit us during chapel.  These children are from Kenya and Uganda and will travel and perform across the United States for six months.  The fifth grade classes and the Daraja choir are pen pals and our KR families have helped support them financially.

After chapel, the teachers who are traveling with them visited my science lab.  Then we heard the singing across the hall.

October 3

Rotocopters

After learning how aerospace engineers use their knowledge of force, motion, and energy, we did several experiments with rockets and helicopters.  Then we took our roto-copters to the rotunda to test them.  We observed what happened when we reversed the blades, put the blades facing the same direction, and changed the weight.  We returned to our classroom and wrote our first lab report.

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October 2

Starch Experiment

After a lesson on starch, we tested for its presence in foods that we eat (cheese, rice, crackers, cucumber, potato, and flour).  Iodine (brown color) will turn blue black when starch is present. Our biggest surprise?  The cheese turned dark blue.  After checking the ingredients, we discovered that potato starch was added to the grated cheese. I researched why it was added and found that it is used to prevent clumping.

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October 2

Oxidation Experiment

We learned that oxidation occurs when an apple is cut open and the tissue is exposed to oxygen.  Rust is also the result of oxidation. The lesson continued with information about how oxidation occurs within our bodies. We discussed the importance of a diet rich in antioxidants.

Many of the children had observed apples turning brown.  Our experiment focused on determining the best liquid to prevent oxidation. We used the scientific method and had a control in this experiment. We concluded that we had the best results with salt water.  Some of the children were surprised that the lemon juice did not work better because they had observed parents use lemon juice to prevent oxidation at home. We added a teaspoon of lemon juice to a cup of water.  We may have had different results with more lemon juice.  Apple juice and Ginger Ale also had positive results.

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