Structural adaptations<span> are physical features of an organism like the bill on a bird or the fur on a bear. Other </span>adaptations<span> are behavioral. Behavioral</span>adaptations<span> are the things organisms do to survive. For example, bird calls and migration are behavioral</span>adaptations<span>.</span>
<span>Valence is defined as number of electrons that are present in the outermost orbital. Oxygen is in the 16th column of the periodic table and the total number of valance electrons is determined by units place digit of the column position which is 6 for oxygen. The outermost orbital is the high energy level and there are two in that orbit. So the valance is +2.</span>
Decaying uranium atoms in the earth's crust result in Radon gas. Radon gas cannot be synthetically or commercially produced. It is produced as the result of the natural breakdown of uranium i.e. decaying uranium atoms. Radon gas is a naturally occurring radioactive gas. People are exposed to Radon gas via the inhalation and ingestion of the gas. Because it is found in the ground, water or building materials, Radon gas can enter work buildings as well as private dwellings.
<span><span>Chaetognaths worms </span>are the transparent worms that prey on the other plankton.
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Decent from a common ancestor; natural selection.
