As explained in the atomic radii section, the effective nuclear charge increases across a period due to the increasing number of protons, and thus it is harder (takes more energy) to remove an electron from the atom. IE increases when you move across a period.
![valence electron trend periodic table valence electron trend periodic table](https://4.bp.blogspot.com/-A7FVxmfGGNI/Tp9bFuBKzmI/AAAAAAAAMmM/tB-bmIcwc44/s1600/periodic%20table%201.jpg)
Thus IE decreases as you move down the group. As the distance increases, the electrostatic force decreases, thus it is easier (takes less energy) to remove an electron from the atom. This decreases the electrostatic attraction between the nucleus and the outermost electron because the electrostatic force is inversely proportional to the distance between two charges, squared (see Coulomb's law). IE decreases as you move down the group because as explained earlier, the outermost electrons are further away as you move down a group. Ionization energy (IE) (the energy needed to remove e- from an atom): This increases the effective nuclear charge felt by the electrons, and the electrons are "pulled" more closely in to the nucleus. However, there are also other patterns in chemical properties on the periodic table. This similarity occurs because the members of a group have the same number and distribution of electrons in their valence shells. This is because as you move across a period (the valence electrons are all in the same shell), the number of protons in the nucleus increases. The elements in groups (vertical columns) of the periodic table exhibit similar chemical behavior. This means the outermost electron is further from the nucleus, and the atomic radius increases.Ītomic radii decrease across a period. This is because as you go down each group on the periodic table, the energy level of the atom increases and you "add" valence electron shells. Atomic radius: Atomic radii increase down a group. I'll discuss the explanation for two trends, and then you can use this logic for other trends like electronegativity, electron affinity, etc:ġ. The easiest method to grasp trends in the periodic table is to look at the number of protons in each atom and the energy level of the atoms. Electronegativity: a measure of how tightly an atom holds onto its valence electrons.
![valence electron trend periodic table valence electron trend periodic table](https://reader034.pdfslide.net/reader034/viewer/2022042700/5558f830d8b42a724c8b49a3/html5/thumbnails/6.jpg)
On the periodic table, first ionization energy generally increases as you move left to right across a period. In regards to locating the different blocks on the periodic table, you simply need to remember this: An elements first ionization energy is the energy required to remove the outermost, or least bound, electron from a neutral atom of the element.