Chlorine has the highest electron affinity while mercury has the lowest. Electron affinity generally increases across a period (row) in the periodic table, due to the filling of the valence shell of the atom.
How do you know which element has more electron affinity?
Nonmetals have a greater electron affinity than metals because of their atomic structures: first, nonmetals have more valence electrons than metals do, thus it is easier for the nonmetals to gain electrons to fulfill a stable octet and secondly, the valence electron shell is closer to the nucleus, thus it is harder to ...
What element has the highest electron affinity?
Chlorine has the highest electron affinity among the elements. Its high electron affinity can be attributed to its large atomic radius, or size. Because chlorine’s outermost orbital is 3p, its electrons have a large amount of space to share with an incoming electron.
What are the exceptions to electron affinity?
In general, exceptions arise when new subshells are being filled/half-filled , or in cases where the atom is too small. In the first case, Be and Mg are interesting examples: they have a positive electron affinity (just like N, in fact) because of the energy difference between the s and p subshells.
Which element has the most negative electron affinity?
Fluorine, therefore, has a lower affinity for an added electron than does chlorine. Consequently, the elements of the third row (n = 3) have the most negative electron affinities.
Why is electron affinity so positive for noble gas elements?
The noble gases present in the group 18 of periodic table, have electronic configuration ns2np6. ... Thus, in case of noble gases, where it resists the addition of electrons, extra energy is required in order to force the electron to bind to the stable atom . Therefore, making the electron gain enthalpies positive.
How do you find negative electron affinity?
In general, elements with the most negative electron affinities (the highest affinity for an added electron) are those with the smallest size and highest ionization energies and are located in the upper right corner of the periodic table .
How do you find electron affinity?
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 because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.
How do you know if electron affinity is positive or negative?
The electron affinity is defined as the energy change that occurs when an atom gains an electron, releasing energy in the process. ... If a reaction is exothermic, the change in energy is negative. This means that the electron affinity is positive .
What is the meaning of negative electron affinity?
Electron affinities are negative numbers because energy is released . The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinities. This means that more energy is released in the formation of a halide ion than for the anions of any other elements.
What does it mean when electron affinity is negative?
Electron affinities are negative numbers because energy is released . The elements of the halogen group (Group 17) gain electrons most readily, as can be seen from their large negative electron affinities. This means that more energy is released in the formation of a halide ion than for the anions of any other elements.
Which noble gas has highest electron affinity?
Neon has the highest positive electrons gain enthalpy.
Do noble gases have a high electron affinity?
Because noble gases have a full octet, their ionization energies are actually quite high . Electron affinity is the amount of energy released when an electron is added to a neutral atom. Because noble gases have stable electron configurations, they have very low electron affinities.
Do noble gasses have high electron affinity?
Electron affinity of noble gas is near zero . Noble gas has completely filled valence shells and stable octets. It does not accept electrons easily as they have no deficiency, also adding electrons produces repulsion between the electrons.
How do you explain electron affinity?
Electron affinity is the energy change that results from adding an electron to a gaseous atom . For example, when a fluorine atom in the gaseous state gains an electron to form F−(g), the associated energy change is -328 kJ/mol.
What do you mean by electron affinity?
1 : the degree to which an atom or molecule attracts additional electrons . 2 : the minimum energy required to remove an electron from a negative ion to produce a neutral atom or molecule.
