Isotopes are different versions of an element or different versions of a certain kind of atom. In order for an atom to be an isotope, it must have the same number of protons because the protons determine what kind of element it is. Also, there must be a different number of neutrons in the core the atom.
You are correct :) To double check, they are adaptation, variation, overproduction, and natural selection
The answer is Alfred Wallace.
Darwin began formulating his theory of natural selection in the late 1830s but he went on working silently on it for twenty years. He wanted to amass a wealth of evidence before publicly presenting his idea. During those years he corresponded briefly with Wallace (right), who was exploring the wildlife of South America and Asia. Wallace supplied Darwin's help publishing his own ideas on evolution. He sent Darwin his theory in 1858, which, to Darwin's shock, nearly replicated Darwin's own.
This question is unfortunately incomplete. The burning of coal containing sulfur can lead to the release of sulfur oxide compounds to the atmosphere. These compounds <span>combine with atmospheric water to form sulphuric acid. Sulphuric acid lowers the pH of atmospheric water vapour, and during rainfall events, precipitated rainfall will be of a low pH (acid rain).</span>