<span> d. Reduced visibility
Acid rain doesn't reduce visibility, smog does
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Multiply .800 moles of O2 by Avagadro's number divided by 1 mole. This will get rid of the moles on the bottom and leave you with molecules. So technically .800 times 6.02x10^23.
Answer is: <span>an atomic radius.
</span>The atomic radius<span> of a </span>chemical element<span> is a measure of the size of its atom.
</span>The atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.
The atomic radius decreases across the periods because an increasing number of protons, because <span>greater attraction between the protons and electrons.</span>