A characteristic which helps an animal to live longer will generally tend to become more common in the population because as the animal produces more offspring those traits are passed down to them. Eventually it will be a common characteristic in the population.
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Just 2 valence electrons.
Hydrogen already has one to start with, as well. With the exception of hydrogen and helium, all other atoms need 8 valence e-
Answer:
3. An oxygen atom with 8 electrons, 8 protons, and 9 neutrons .
Explanation:
if an atom contains equal numbers of protons and electrons, the atom is described as being neutral.
