What is the trend in Atomic Radii? Which elements have a bigger Radius?
Answers
HI,
show 1 more comment
up vote1down vote
If you want to compare the radius of 2 elements, you can usually do it when the elements are either on the same column (group), or the same row (period).
When you move down the column, the element becomes bigger, because it has more energy shells. For example, Oxygen has a smaller radius than Sulfur.
When you move right the row, the element has larger nuclear charge (more protons) for the same number of energy shells. Therefore, each electron is pulled stronger and the radius decreases. For example, Fluorine has a smaller radius than Oxygen.
Now, your elements, Berylium and Xenon, are not in the same column nor row. Nevertheless, Xenon is much lower than Berylium so we might assume that it has a larger radius.
HOPE IT HELPS!
Periodic Trends of Atomic Radius. An atom gets larger as the number of electronic shells increase; therefore the radius of atoms increases as you go down a certain group in the periodic table of elements. In general, the size of an atom will decrease as you move from left to the right of a certain period.
Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.