Chemical Properties of Hydrogen - The Galloway School

In tandem with a lesson about Dmitri Mendeleev, the inventor of the Periodic Table, these eight grade students do a laboratory experiment in which they test some of the chemical properties of hydrogen and oxygen, as Mendeleev would have done to make his cards.

In the late 1860s, Dmitri Mendeleev, the inventor of the periodic table, was writing a textbook. Several people were looking for ways to organize the elements, but no one had come up with a satisfactory method. Mendeleev decided to see what he could do. He wrote everything he knew about the elements on small cards, one for each element, and then he began to play chemical solitaire, arranging the elements in order based on different properties. After considerable trial and error, he recognized that if the elements were arranged in order of atomic mass, periodic patterns in the properties emerged. He was able to produce what later became known as the periodic table of elements, very similar to the modern table. With it, he was able to predict the existence of undiscovered elements and their properties with remarkable accuracy.

In her classroom, Lynn Gaar asks her eighth grade students to walk in Mendeleevs shoes. She gives them recreations of Mendeleevs element cards and assigns them the task of finding a way to organize those elements. They are also given an unknown card, which they are asked to fit into the pattern and predict its properties. First they might choose, for example, electronegativity as a basis. The students then shift the cards around to put the elements in order based on this property to see if they can recognize any patterns. In fact, this property does not work well, so they try another, and so on. Eventually, they find that atomic mass works best, and place the unknown. They then graph their results to show which of the properties show patterns and which (such as melting point and density) do not.

This lesson integrates their math and science studies (since it involves graphing), and, by allowing the students to physically move the cards around, it enables them to discover patterns among the elements for themselves. Rather than learning about Mendeleev in a book, they are asked to become Mendeleev. Rather than memorizing the patterns represented in the periodic table, these students are asked to discover them on their own. At one level, it is an exercise in logic and pattern recognition, but, as it relates to real information, it serves as a valuable introduction to concepts they are studying.

In tandem with this exercise, the students do a laboratory experiment in which they test some of the chemical properties of hydrogen and oxygen, as Mendeleev would have done to make his cards.

Category:

Education

Tags:

• School
• Education
• Galloway
• Science
• Lab
• Experiment
• Hydrogen
• Mendeleev

[Brightred11]

@hunggtran yep, 2H2 + O2 ----> 2H2O In fact I am teaching that very lesson tomorrow.

[VelezKeanu]

best 8th grade class