electron affinity

[705676154]

How do we find electron affinity?

[Fiona H 2E]

Hi! The less valence electrons an atom has, the least likely it will gain electrons. Electron affinity decreases down the groups and from right to left across the periods on the periodic table.

The equation for electron affinity is: X(g) + e- -> X-(g)

[Emily Ngo 1E]

Hi,
electron affinity is defined as the degree to which an atom or molecule attracts additional electrons. So on the periodic table, electron affinity generally decreases down a group of element.

[SarahOMalley1D]

Hi! Compared to other trends of the periodic table, electron affinity tends to be a bit less periodic. It generally increases as you move across as period because elements in the p-block wish to gain electrons to fill their valence shell and reach a more stable state. A high electron affinity means that an element releases lots of energy when it gains an electron. This means that the atom wanted an electron. Some atoms will require energy (absorb energy) to gain an electron, and they will have a low electron affinity.

[Claudia Longo 2J]

How do we find electron affinity?

Electron affinity is not typically a specific value that we as students will have to find in Chem 14A, rather it is a trend that we are expected to identify. On the periodic table, electron affinity increases up the periods and across the groups. However, in some problems we may be given electron affinity values and be expected to understand say, which atom will have the shortest bond length with Hydrogen or another element.