Does electron affintity increase from left to right on the periodic table?
And are there any trends for the groups?
http://en.wikipedia.org/wiki/Electron_affinity#Values_for_the_elements
Thanks :)
Yes, electron affinity generally increases from left to right on the periodic table.
To understand why this is the case, we need to consider the concept of electron affinity. Electron affinity is the energy change that occurs when a neutral atom gains an electron to form a negatively charged ion. It is a measure of an atom's ability to attract additional electrons.
As you move from left to right across a period on the periodic table, the number of protons in the nucleus increases, leading to a greater positive charge in the nucleus. This greater positive charge exerts a stronger pull on the negatively charged electrons. This increased attraction makes it easier for an atom to accept an additional electron, resulting in a higher electron affinity. Therefore, electron affinity generally increases as you move from left to right across a period.
Regarding trends for the groups on the periodic table, there is no consistent pattern for electron affinity within a group. Electron affinity tends to decrease as you move down a group. This is because as you move down, the outermost electrons are located in higher energy levels, which are farther away from the nucleus. The increased distance weakens the attractive force between the nucleus and the external electron, leading to a lower electron affinity. However, there may be some exceptions and variations in certain groups due to specific electron configurations and other factors.