Over time, an iron nail reacts with water to produce iron oxide, or rust. Which of the following is a signal that rusting has taken place?

Question

A.
a color change on the nail from silver to reddish-brown
B.
the release of heat and steam at the area where the mixture occured
C.
the appearance of sparks
D.
the release of an odor and the presence of bubbles

Answer 1

The correct answer is:

A. a color change on the nail from silver to reddish-brown

This color change is a clear indication that rusting has occurred, as iron oxide (rust) typically has a reddish-brown color. The other options do not specifically indicate rusting.