Science Teaching Series

Internet Resources

I. Developing Scientific Literacy

II. Developing Scientific Reasoning

III. Developing Scientific Understanding

IV. Developing Scientific Problem Solving

V. Developing Scientific Research Skills

VI. Resources for Teaching Science

Activity 19.1 – Choosing the right material

By 1700, only 14 elements (carbon, sulfur, iron, copper, zinc, arsenic, silver, tin, antimony, gold, mercury, lead, bismuth, and phosphorous) and a few compounds were known. The industrial revolution, which began in the 18th century, established a demand for new resources, and gave incentive for chemists to purify, develop, and classify new materials.  The phenomenal expansion in commercial products that occurred in the industrial age is a direct result of the development of the chemical and materials sciences.  Materials science focuses on the properties of materials that make them suitable for industrial applications.  Chemists have now have identified more than 110 elements, more than 23,000,000 compounds, and are identifying more than 4000 new compounds per day.  It is impossible for developers to remember the properties of so many substances, yet they must select the best compounds to produce the best products for today’s competitive market.  Developers rely upon electronic databases to search for materials with desired characteristics.  In this activity, you will use a database file of the elements (table 19.2) to search for those with the specified properties.  Download the elements file or enter the data from table 19.2 into a new file.

circuit(1) Electronic circuits:  When designing electronic circuits, computer hardware engineers must use materials that have extremely high conductivity so signals travel easily with little loss of energy.  Sort (arrange) the database list on electrical conductivity to determine the three best elements for use in electric circuitry.  Where are these three elements found in the periodic table?  Perform an Internet search to determine if these elements are indeed used in electrical circuits.

(2) Aircraft design:  Aircraft designers need materials that can withstand extreme temperatures and are lightweight, malleable, and abundant.  Determine the element that best fits these criteria. Using a filter, select those substances that are metallic (all metals are malleable), have a melting point in excess of 600K, and a density less than 3 g/cm3.  Finally, sort these elements by abundance in the earth's crust to determine which is the most abundant.  Which element fills these criteria?  Perform an Internet search to determine the element of which most airplanes are made.  Is this the same element you selected using your database filter?

(3) Electric switches:  Certain applications require fluid conductors materials that conduct electricity and yet flow at room temperature.  Perform a record selection (filter) for those elements with a melting point less than 298K, and a boiling point greater than 298K.  This selects for those elements that are liquid at room temperature, 298K (25°C).  Following this record selection (filter), sort descending on electrical conductivity.  The element at the top of the list will be the best liquid conductor at room temperature. What is this element?