I don't know how to answer the true or false however it can take around 4 weeks in the peak of the summer climate.
What this student is doing is collecting data. So, he wants to check how many life forms there are in the waters nearby. In order to do so, he has to take a sample, and look at it through a microscope so as to determine the number. So, he collected a sample which is his data. He is not drawing conclusions yet, but rather counting these organisms. He is not making a peer review - his peers aren't even mentioned here. He is not forming a hypothesis because he is just counting at this point.
B. An atom whose nucleus is unstable and emits particles and and energy. This is a Radioactive isotope.
The atomic nuclei of constituent atoms of the same element include the same number of protons but different numbers of neutrons. Radio isotopes are an element's radioactive isotopes. They can alternatively be described as atoms with an excess of energy in their nucleus or atoms with an unstable ratio of neutrons to protons. A radioisotope's unstable nucleus can form either spontaneously or as a result of a deliberate alteration of the atom. Radioisotope production can occur using either a cyclotron or a nuclear reactor. Molybdenum-99, which has a high neutron content, can be produced most effectively in nuclear reactors, whereas fluorine-18, which has a high proton content, can be produced most effectively in cyclotrons. Uranium is the most well-known illustration of a radioisotope that is found naturally. Uranium-238 constitutes all naturally occurring uranium with the exception of 0.7%.
Learn more about Radioisotopes
brainly.com/question/19472025
#SPJ9
Acetylcholine..
hope it helps