For question number one
A pressurized water reactor indirectly heat water from the core.
Supercritical mass results to an increase in the rate of fission. There is a chain reaction that will occur. Nuclear fission or explosion used in atomic bombs relies on supercritical mass. An atom splits into two, with each splitting into two pairs and so on, releasing energy in each step.
Options are provided in the given question, so the complete question is as follows:
Laboratory equipment is cleaned and properly stored after use primarily so that —
A. chemical products can be measured and recorded as data
B. time is saved in setting up the next experiment
C. toxic materials can be kept in the laboratory
D. the possibility of contamination in the laboratory is minimized
Answer:
D. the possibility of contamination in the laboratory is minimized
Explanation:
After the completion of experiments, all the laboratory equipment should be cleaned and properly stored to minimize the possibility of contamination in the laboratory.
Any contamination in the laboratory can affect the experiment and will not give an accurate result, so it is important to clean and store the equipment properly.
Hence, the correct answer is "D".