Iron is the most common element forming the planet Earth and can be found in Earth's outer and inner core. It is the fourth most common element in the
Earth's crust as well. Fresh iron surfaces appear silver-gray, but rusts easily in
normal air. It is a solid at room temperature, but it is a soft metal. It is
malleable and used for many tools and utensils. Iron is attracted to a magnet
and can be magnetized. The melting point of iron is 2800°F.
Iron filings were mixed together with salt crystals. What unique property of
iron would be best to separate the filings from the salt?