Academic journal article The Science Teacher

Chemical Solitaire: Arranging Cards to Build an Organizational Model of the Elements

Academic journal article The Science Teacher

Chemical Solitaire: Arranging Cards to Build an Organizational Model of the Elements

Article excerpt

The periodic table does more than provide information about the elements. The periodic table also helps us make predictions about how the elements behave. Understanding the atomic structure of matter and periodic properties of the elements, as shown in the periodic table, is fundamental to many scientific disciplines. Unfortunately, high school students often view the periodic table as an overwhelming jumble of numbers and letters to be memorized, rather than a model with predictive and explanatory power.

This article presents an activity that uses the rich history of the development of the periodic table to promote understanding of how the elements are organized. By arranging three sets of cards, students connect to the individuals in history whose creativity and imagination laid the groundwork for our evolving comprehension of the patterns in nature. This activity, which has strong connections to the Next Generation Science Standards (NGSS Lead States 2013) (see box, p. 49), can be accomplished in as few as two class periods with little prep time or cost.

Improving students' understanding of the nature of science has been an ongoing goal for more than 50 years (Lederman 2007). This activity focuses on three of the nature of science understandings defined by the NGSS: scientific knowledge is open to revision in the light of new evidence, scientific knowledge is based on empirical evidence, and science is a human endeavor (NGSS Lead States 2013). Over the 124 years modeled in this activity, advancements in technology allowed for the discovery of new elements and elemental properties, and scientists modified existing elemental organization paradigms to accommodate the new evidence. Similarly, students in this activity revise scientific explanations based on new evidence as they develop classification strategies for the elements. At the end, students reflect on their reasoning and compare their organization schemes to those of their peers and historical scientists.

[ILLUSTRATION OMITTED]

Element cards

Historical lore says that Russian chemist Dmitri Mendeleev (1834-1907) (Figure 1) wrote the weights and properties of the elements on cards and played "chemical solitaire," organizing them. Although no such cards have been found, the analogy to the popular card game is a useful teaching tool and encourages students to think of multiple ways of classifying the elements. In solitaire, cards are organized by suit and value. Mendeleev developed a periodic table organized by both weight and properties.

In this activity, element cards (provided online; see "On the web") are divided into three sets that correspond to significant advancements in our understanding of how the elements are organized (Figure 2). The colors named below for the card sets correspond to the colors in Figure 2.

* Set A (1789; green): The elements in the list of simple substances that French chemist Antoine-Laurent Lavoisier (1743-1794) developed that correspond to our modern understanding of elements (N=27). The indicated year, 1789, is when Lavoisier published his table; 27 is the number of elements he listed that correspond to our modern understanding of the term.

* Set B (1869; gold): The additional elements known at the time that Mendeleev constructed his first periodic table (N=30).

[FIGURE 1 OMITTED]

* Set C (1913; blue): The additional elements known when English physicist Harry Moseley (1887-1915) rearranged the periodic table based on atomic number (N=11).

[FIGURE 2 OMITTED]

This progression of card sets scaffolds the number of elements students have to manipulate at a time, follows historical discovery, and allows students to arrange more familiar elements first. The year 1913 was chosen for the final card set because it allows students to add the noble gases to their element arrangement and "fill in" some of the potential gaps in their models. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.