Will the demise of the US penny damage science education?
Robert P Crease wonders what the death of the US penny will do to how we teach and learn science The post Will the demise of the US penny damage science education? appeared first on Physics World .
The demise of the US penny, announced in 2021 by President Trump, has raised concerns among educators and science enthusiasts about its impact on science education. While the decision to stop minting pennies due to their production cost is a practical move, the penny has been more than just a coinтАФit has been a vital tool in teaching and learning science, particularly in the realm of chemistry and physics.
The US penny has a rich history dating back to 1793, and its presence in everyday life has made it an accessible resource for students to explore scientific concepts. For many, the penny introduced them to the world of science through simple experiments and observations. One such concept was corrosion, a process that the penny exemplified. Until the early 1980s, pennies were made of 95% copper, which gradually oxidized, turning green. This transformation was not only visually striking but also provided a real-world example of chemical reactions. Students learned that the Statue of Liberty's iconic green color is a result of copper oxidation, a fact that sparked curiosity and interest in the scientific process.
In school laboratories, pennies were often used to demonstrate corrosion through a hands-on experiment. By immersing a penny in a solution of salt and vinegar, students could observe the gradual change in color, akin to the natural oxidation process. Even more effective was the use of plant food like Miracle Gro, which contains ammonia, accelerating the reaction and producing a lighter shade of green. Cleaning off the green patina with an acid like lemon juice further deepened students' understanding of chemical interactions.
The penny also played a role in teaching surface tension, a fundamental principle in physics. By placing a drop of water on the surface of a penny, students could witness the dome-like shape formed due to the cohesive forces between water molecules. This simple observation provided an entry point into the study of fluid dynamics and capillary action.
In the realm of electrochemistry, pennies were instrumental in demonstrating the principles of electroplating. Students learned about ions and electrical conductivity by placing pennies and steel nails in a salt and vinegar bath. The nails would electroplate with copper, while the pennies would electroplate with zinc. This experiment not only taught the basics of electrochemical reactions but also highlighted the importance of inert electrodes and the role of ions in these processes.
Additionally, pennies were used to teach density, a concept crucial in various scientific disciplines. With a diameter of 19 mm and a thickness of 1.52 mm, pennies provided a convenient size for measuring volume and mass. By submerging pennies in a graduated cylinder to determine their volume and weighing them to find their mass, students could calculate density, a foundational concept in physics and chemistry.
The change in penny composition from 95% copper to 97.5% zinc in 1983 added another layer of learning. Students had to become adept at distinguishing between old and new pennies, as they were only plated with copper. This not only tested their observational skills but also introduced them to the concept of alloying and the role of surface layers in material properties.
As the US penny transitions to digital currency and cashless transactions, its physical presence in daily life will diminish. While the decision to discontinue the penny is economically sound, its absence from science classrooms may leave a gap in how students engage with certain scientific concepts. The penny's role as a tangible object that bridged the gap between theory and practice in science education cannot be overstated.
In the face of budget cuts and the termination of science agencies, the loss of the penny may seem trivial. However, it serves as a reminder of the importance of accessible, hands-on resources in fostering a deeper understanding of scientific principles. As the world becomes increasingly digital, the need for such tangible tools in education becomes even more critical. The demise of the US penny may not be a significant blow to science education, but it does underscore the necessity of finding alternative, practical objects that can continue to inspire and educate future generations in the realm of science.
