A. The atomic radius increases (in a group) with the increasing atomic number. This is because atomic size generally increases from top to bottom within a group because the greater the number of protons means the greater amount of electrons. The amount of electrons in orbitals determine an atom's size/radius.
B. Since Group 1A (Alkali Metals) are metals, they tend to form cations. Cations are always smaller than their original atom because the greater positive charge from the nucleus closes in the space between it and the electrons, thus "shrinking" its size. This is why the ionic radii are smaller than the atomic radii of the same element.
There are no states in the picture, but Na should have a "(s)" after it, and Cl2 should have a "(g)" after it. NaCl should have an "(s)". Chlorine is a diatomic element so it has a "2" subscript on it.
