How do you explain electron affinity?
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How do you explain electron affinity?
electron affinity, in chemistry, the amount of energy liberated when an electron is added to a neutral atom to form a negatively charged ion. The electron affinities of atoms are difficult to measure, hence values are available for only a few chemical elements, chiefly the halogens.
What is the trend of electron affinity?
What is the trend for electron affinity? Electron affinity increases upward across periods of a periodic table for the groups and from left to right, because the electrons added to the energy levels get closer to the nucleus, making the nucleus and its electrons more attractive.
What does a positive electron affinity mean?
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.
Why electron affinity of nitrogen is positive?
Since electron affinity is associated with the “love” for acquiring another electron, and the new electron would be added in one of the singly-occupied p orbitals, we have a problem. This extra energy needed to overcome the repulsion makes the electron affinity positive.
Why are electron affinities of Be and Mg positive?
Electron gain enthalpies of Be and Mg are positive because of the following reasons: They have fully filled s orbitals and addition of new electron would move to the higher energy p . 3. This addition of new electron is very energetically unfavorable and so this accounts for the more positive electron affinity.
Which of the following elements has a positive value of electron affinity?
Electron affinity is the tendency to accept electron and Be and Mg instead of gaining electron they prefer to loose electron to attain noble gas configuration. hence energy is supplied to them to accept an electron. Therefore they have positive value for electron affinity.
Why are electron affinities 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.
Why electron gain affinities of Be and N are almost zero?
electron affinity of Be, Mg, N are almost zero explain Be 1s22s2 has a filled valence shell, so it does not have the tendency to gain electrons. The 2p subshell contains half filled configuration which becomes unstable on addition of one electron in 2p sub-shell. Therefore electron affinity of nitrogen is almost zero.
Which set of elements shows positive electrons?
As it has half-filled p-orbital so, it is stable in nature. Therefore, to add an electron into it’s p-orbital will require high heat energy. Hence, nitrogen will have positive electron gain enthalpy. Thus, we can conclude that the set N, He, Ne elements shows positive electron gain enthalpy.
How does electron affinity compare?
A more negative electron affinity corresponds to a greater attraction for an electron. (An unbound electron has an energy of zero.) As with ionization energy, there are two rules that govern the periodic trends of electron affinities: Electron affinity becomes less negative down a group.
Why is electron affinity positive and negative?
Unlike ionization energies, which are always positive for a neutral atom because energy is required to remove an electron, electron affinities can be negative (energy is released when an electron is added), positive (energy must be added to the system to produce an anion), or zero (the process is energetically neutral) …
How do you determine electron affinity?
Electron affinity can be measured by the amount of energy released when an electron is added to an atom to form a negative ion.
What element has the most negative electron affinity?
Answer Wiki. Chlorine has the most negative electron affinity. In chemistry and atomic physics , the electron affinity of an atom or molecule is defined as the amount of energy released when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.
What does an electron affinity with a negative value indicate?
If the value of electron affinity or Eea is negative, it means energy is required to attach an electron . Negative values are seen for the nitrogen atom and also for most captures of second electrons. It can also be seen for surfaces, such as diamond.
Which element group have the most negative electron affinities?
Most negative = fluorine. Electron affinity indicates the energy released if an atom attracts electrons.