Answer:
At the very bottom
Explanation:
When examining a cross section of rock layers, the oldest layer is on the bottom. This is because over time, newer rock layers continued to form on top of the oldest one.
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
The answer would be cerebrovascular disease
Hope this helps ! # And I oop
<span>Bacteria is needed to convert nitrogen gas/ammonia into nitrates for "enhancing" the growth of plants.</span>
