Section 3
Periodic Trends
By Boundless
![Thumbnail](../../../../../../figures.boundless-cdn.com/9936/square/20of-20element-20chlorides.jpg)
The physical properties of elements vary across a period, mostly as a function of bonding.
![Thumbnail](../../../../../../figures.boundless-cdn.com/10094/square/allic-20and-20non-metallic.jpg)
The physical properties (notably, melting and boiling points) of the elements in a given group vary as you move down the table.
![Thumbnail](../../../../../../figures.boundless-cdn.com/24314/square/blocks.jpg)
The electron configuration of a given element can be predicted based on its location in the periodic table.
![Thumbnail](../../../../../../figures.boundless-cdn.com/9891/raw/periodic-trends.jpg)
Atomic radii decrease from left to right across a period and increase from top to bottom along a group.
![Thumbnail](../../../../../../figures.boundless-cdn.com/30037/square/atomic_&_ionic_radii.jpg.jpg)
Similarly charged ions tend to decrease in size across a period (row) and increase in size down a group (column).
![Thumbnail](../../../../../../figures.boundless-cdn.com/10052/square/nizationenergyatomicweight.jpg)
The ionization energy tends to increase as one moves from left to right across a given period or up a group in the periodic table.
![Thumbnail](../../../../../../figures.boundless-cdn.com/10092/square/electron-20affinity.jpg)
The electron affinity of the elements generally increases across a period and sometimes decreases down a group in the periodic table.