Question

how are vertical control rods used in a nuclear reactor? answer options: select one of four theyre made thin to expose as few molecules as possible to neutron bombardment. theyre melted down as they enter the reactor. theyre moved in and out of the reactor to control the chain reaction. theyre removed to prevent a chain reaction.

Explanation:

To determine the correct answer, we analyze each option:

• Option 1: Control rods are designed to absorb neutrons, not minimize exposure. Making them thin to expose few molecules to neutron bombardment is incorrect.
• Option 2: Control rods are not melted down when entering the reactor. This is not their function.
• Option 3: Control rods in a nuclear reactor are moved in and out to control the chain reaction. By adjusting their position, they can absorb more or fewer neutrons, thus controlling the rate of the nuclear chain reaction. This is the correct function.
• Option 4: Removing control rods would increase the chain reaction, not prevent it. To prevent a chain reaction, control rods are inserted, not removed.

Answer:

C. They're moved in and out of the reactor to control the chain reaction. (Note: Assuming the options are labeled A, B, C, D with the third option being C. If the original labeling is different, adjust the identifier accordingly, but the text of the option remains the same.)