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>
C. Theres decreased Biodiversity Most likely because of natural or human causes (deforistation)
The correct answer is A. The magnetic field is strongest at the north pole and the south pole of a bar magnet. At the poles, the magnetic field is equally strong while the force is weaker at the middle of the bar. The field lines are closely packed at each pole and it gets wider as the lines get further from the pole.