Final answer:
To measure the copper content of pre-1982 coins, the experiment would need to include a method like acid digestion followed by spectroscopic analysis, such as AAS or ICP-OES, to obtain the accurate copper concentration.
Step-by-step explanation:
To determine the copper content of coins minted before 1982, one specific modification to the current experiment would be incorporating acid digestion followed by spectroscopic analysis. This process involves dissolving the coin in acid to convert all the solid metal components into their ionic form. Subsequently, techniques such as atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) are used to measure the concentration of copper ions in the solution. The results would indicate the quantity of copper that was in the coin.
These modifications are essential because pre-1982 pennies contain a significantly higher copper content compared to those minted after 1982, which are primarily made of zinc with a thin copper plating. Hence, to accurately quantify the amount of copper in these older coins, a method that can precisely measure the highly concentrated copper is required.