Answer:It has the lowest effective nuclear charge of the four new elements.
The average atomic mass of the element is the sum of the products of the percentage abundance of isotope and its mass number. Therefore, for atomic mass equal to 58.933, the most abundant isotope is cobalt-59. Thus, the answer is letter C.
In an exothermic reaction, heat is transferred to the surrounding.
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Answer:
heat energy is released into the surrounding