Atomic radius increases down the columns and to the left. The furthest left elements are Na and Cs. Cs is furthest down so it is the biggest.

Atomic radius will decrease as you move to the right, because the atomic number of the element will be increasing. This results in a more positively charged nucleus that pulls the electrons closer to the center. As a result, atomic radius will notably decrease from left to right.

Electronegativity, ionization energy, and electron affinity all increase to the right of the periodic table.

When predicting how atomic radius will change as you move along the periodic table, remember these two trends.

1. As you move down the table in a given group, the atomic radius of the atoms will increase.

2. As you move left to right in a given period, the atomic radius will decrease.

Knowing this, we can compare the possible options. Sulfur and chlorine are in the lowest period, so they have the largest atomic radii. Because sulfur is to the left of chlorine on the periodic table, it will have a larger atomic radius. As a result, sulfur has the largest atomic radius out of the possible options.

The transition metals are capable of losing various numbers of electrons from the s and d orbitals of the valence shell. Metals such as Cu, Fe, and Mn have various oxidation states and can form many different ionic compounds.

The trend for electron affinity increases upwards through a group, and rightwards along a period. The noble gasses already have full octets, so the increasing trend stops at the halogens and the noble gasses have extremely low values. The element with the highest electron affinity is fluorine. Halogens tend to have a high values so that they can complete their almost full valence shells. Bromine has a very high electron affinity, while the bromide ion does not because it has already filled its valence octet.

From left to right on the periodic table, atomic radius decreases because the number of protons increase while electrons are being added to the same shell; the attraction between the nucleus and the electron cloud override the shielding effect of adding electrons to the same shell. Therefore, those on the left are larger. From top to bottom on the periodic table, atomic radius/size increases because electrons are added to new valence shells significantly further from the nucleus than the previous shell. Therefore, those on the bottom left are largest.

Helium has the smallest atomic radius. This is due to trends in the periodic table, and the effective nuclear charge that holds the valence electrons close to the nucleus. Atomic radius decreases as you move across a period from left to right and decreases as you move up a group from bottom to top. Since He is at the upper right-hand corner of the table, it must have the smallest atomic radius.

Each of these species has the same electron configuration (that of ). The chloride nucleus has the fewest number of protons, meaning a weaker attractive force between it and the electron cloud. As a result, the atom is more disperse than the others which have larger atomic numbers (and more protons) with the same number of electrons.

The trend for radius is that it increases down and to the left

The periodic table allows you to follow general guidelines or "trends" that are displayed on the table. Atomic radius is one such trend. As you move down in groups, further shells are added to the atom which results in an increase in radius. As you move to the right on the periodic table, the nuclear charge increases which pulls the elctrons closer to the nucleus. As a result, the atomic radius will decrease when moving to the right.