Which images show chemical reactions?

a. melting ice
b. mixture of nuts, bolts, and washers
c. rusted nails
d. pastries

(more than one answer just an fyi)

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium

Remember that rust prevented by placing a sacrificial electrode in electrical contact with the iron. the sacrificial electrode must be composed of a metal that  oxidizes  more easily than iron (that is, it must be below iron in table 18.1).

The answer is:   [d]:   "ultraviolet" {"  uv  "} .

Burned piece of steel wool does not gain mass. so only d could be true.