What Is The Trend Of Electron Affinity?

What causes electron affinity trend?

Electron affinity increases from left to right within a period.

This is caused by the decrease in atomic radius.

Electron affinity decreases from top to bottom within a group.

This is caused by the increase in atomic radius..

What is Oxygen’s electron affinity?

Electron Affinity of Oxygen is 141 kJ/mol. Electronegativity of Oxygen is 3.44. … An atom of Oxygen in the gas phase, for example, gives off energy when it gains an electron to form an ion of Oxygen.

Which of the following has lowest electron affinity?

oxygenThe electron affinity for oxygen is lowest.

Why is CA bigger than ca2+?

Ca atom will be larger than Ca2+ because cations are smaller than their parent atom. The Ca2+ cation is larger than the Mg2+ cation since the calcium cation has one more complete level than the magnesium cation.

What is a positive electron affinity?

Lesson Summary. The electron affinity is the energy change when an atom gains electrons. The convention is that the higher or more positive the electron affinity value, the more readily the atom accepts an electron.

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.

Why is the electron affinity of CL higher than F?

On comparing chloride ion with fluoride ion we find that electron density per unit volume in fluoride ion (F−) is more than in chloride (Cl−) “ion. This means that coming electron in fluorine atom finds less attraction than in chlorine atom. Consequently, electron affinity of chlorine is higher than that of fluorine.

What is difference between electronegativity and electron affinity?

Electronegativity is defined as a chemical property which decides the propensity of an atom to attract an electron. In the year 1932, Linus Pauling proposed the concept of electronegativity. Electron affinity is defined as the amount of energy liberated when a molecule or neutral atom acquires an electron from outside.

What is electron affinity and what are its periodic trends?

The electron affinity of an atom or molecule is the propensity for that particle to gain an electron. … Electron affinity generally increases across a period in the periodic table and sometimes decreases down a group. These trends are not necessarily universal.

What trend in electron affinity do you see as you go down a group family?

Definition: The energy given off when a neutral atom in the gas phase gains an extra electron to form a negatively charged ion. 1) As you move down a group, electron affinity decreases. 2) As you move across a period, electron affinity increases.

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.

Why is the electron affinity of N lower than either C or O?

This happens because effective nuclear charge, which is a measure of what the net positive charge felt by the electrons is, increases. This implies that the atomic size of carbon will be a little bigger than that of nitrogen, which in turn will be a little bigger than that of oxygen.

Which atom has the largest atomic radius S or O?

Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.

Which element has the highest electron affinity?

ClTherefore Cl has the highest electron affinity.

What element has the most negative electron affinity?

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.More items…•

Is electron affinity positive or 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) …

Why does nitrogen have no electron affinity?

Because nitrogen is relatively stable on its own, it has a relatively low electron affinity. It is similar to the reason that chromium has an unusual valence shell configuration.

Do noble gases have high electron affinity?

Large atoms have low ionization energy and low electron affinity. Therefore, they tend to lose electrons and do not tend to gain electrons. … Any electrons added to a noble gas would have to be the first electron in a new (larger) energy level. This causes the noble gases to have essentially zero electron affinity.

Why does atomic size increase down a group?

In general, atomic radius decreases across a period and increases down a group. … Down a group, the number of energy levels (n) increases, so there is a greater distance between the nucleus and the outermost orbital. This results in a larger atomic radius.