Astudent dips a strip of metal into a liquid. which is evidence that only a physical change has occurred? the metal bends more easily. the metal changes color. the metal gives off light. the metal gives off heat.

Option (a) is the correct answer.

Explanation:

A change which brings no chemical change in composition of the substance is known as a physical change.

For example, bending of metal strip is a physical change as it does not change the chemical composition of substance.  

Whereas metal changes color, metal gives off light, and metal gives off heat are all chemical changes.

Thus, we can conclude that out of the given options, the metal bends more easily is evidence that only a physical change has occurred.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.