Answer:
The correct options are: a. the number of additional neutrons of an isotope is too large; d. the number of additional neutrons of an isotope is too small
Explanation:
The chemical elements that have the same number of protons in the nucleus but different number of neutrons are known as isotopes. Isotopes can be stable or unstable.
The isotope having an unstable nucleus, due to the presence of additional neutrons in the nucleus of the atom, is known as a radioisotope.
Also, chemical elements that have atomic number greater than 83 have unstable nuclei and thus they are called radioisotopes.
It created jobs for the US and increased employment and incomes as well and also lowered prices
The Great Barrier Reef is special because it is by far the largest reef in the world. It is consisted of around 2,900 individual reefs. The size of this reef is approximately as the size of Germany. There are over 900 islands that are stretched over 2,600 km along the the reef. The Great Barrier Reef is so marking and big, that even though it is below water it can actually be seen from space. The ecological importance of this reef is enormous as it is a home for thousands of species, with approximately 10% of all fish species in the world living in it. Because of its beauty and numerous attractions, the Great Barrier Reef is one of the most visited tourist destinations, and the Australian economy manages to generate between 5 and 6 billion Australian Dollars annually from it. Unfortunately, all of the human activity has been affecting this reef very negatively, and little by little part of it is dying out.