Question

electrochemical energy is produced when: select one: a. the sun shines on photocells. b. the steam builds. c. when two dissimilar metals are heated. d. two dissimilar metals are immersed in an acidic liquid.

Explanation:

Electrochemical energy is produced in a galvanic cell. A galvanic cell consists of two dissimilar metals (electrodes) immersed in an electrolyte (like an acidic liquid). The sun shining on photocells (option A) is related to photovoltaic energy. Steam building (option B) is more relevant to thermal - mechanical energy conversion. When two dissimilar metals are heated (option C), it is related to thermoelectric effects (like the Seebeck effect), not electrochemical energy. In a galvanic cell (option D), a redox reaction occurs between the two metals and the electrolyte, generating an electric current (electrochemical energy).

Answer:

D. two dissimilar metals are immersed in an acidic liquid.