A number of simple experiments make use of the fruit, including an activity using lemon juice to demonstrate oxidization.
According to the University of Illinois, the United States is the second leading producer of apples, one of the most widely cultivated fruits in the world. Many science experiments make use of the fruit, from simple activities for younger students that utilize water to illustrate buoyancy, to slightly more sophisticated experiments that use other household materials to demonstrate how Egyptians produced their iconic mummies.
Using Apples to Observe Growth Patterns
Adopt and plant an apple tree near a class window to observe the growth of the apples and the tree itself. Record the tree's progress on a variety of graphs, and collect the tree's leaves in a field book. Various websites offer virtual tours of orchards for those who cannot plant or adopt a tree, while also allowing students to observe and take notes of different varieties of trees and apples. Likewise, you can observe the trees during different times of the year to show the effect of the seasons on the tree's growth and the maturity of its apples. Students may also take advantage of their school's library to research apple varieties and their seeds, then compare their research with their class tree.
Using Apples to Illustrate Oxidization
Place sliced apples in a bowl and sprinkle them with lemon juice to observe the effects of simple acids and bases on the oxidization process. Apples turn brown when iron-rich chemicals inside apple cells react with the oxygen in the air. The same thing happens to iron objects when they rust. By cutting open the apple, protective cell walls are damaged and the cells are exposed. The acid in the lemon juice will stall the oxidization process, preventing the apples from browning. To add to this activity, use another bowl in which you can sprinkle apples with lemon juice, then baking soda. The bases in the baking soda will cause the lemon juice to bubble, neutralizing the acids and causing the apples to brown normally.
Using an Apple to Illustrate Decay
A naturally occurring mineral found in dry lakebeds, Egyptians used natron in the process of mummification as a water absorbent as well as a drying agent. You can mix simple household ingredients to form a natron solution consisting of table salt, sodium carbonate and baking soda. Seal an apple in a plastic bag containing the natron solution and allow the bag to sit, in order to witness the mummification process. Essentially, the natron solution absorbs all moisture and thus, the source of decay preserves the apple much like it would preserve a human. The sodium carbonate works as a drying agent would on the human body by drawing out all moisture, while the sodium bicarbonate in the baking soda reacts with the extracted moisture to increase the pH level, killing the bacteria that would normally decay the apple.
Using an Apple to Illustrate Density
Illustrate simple physics with apples, namely properties like density and buoyancy. Place an apple and carrot in a large bowl of water wherein the carrot sinks and the apple floats. Essentially, 80% of an apple's volume is air and since the apple is composed of lightweight materials spread out within a larger object, it is less dense than water, which causes the apple to float. Because the carrot contains considerably less air and comprises heavier materials condensed into a smaller object, its density is greater than that of water, which causes the carrot to sink.
Tags: lemon juice, baking soda, natron solution, Apple Illustrate, drying agent
