Ionization Energy (8.2.2) Flashcards
• Ionization energy (IE) is the energy necessary to remove an electron from an
atom, molecule or ion.
• Ionization energy (IE) is the energy necessary to remove an electron from an
atom, molecule or ion.
• Moving down a group, ionization energy decreases because of increased electron
shielding.
• Moving down a group, ionization energy decreases because of increased electron
shielding.
• Moving across a row from left to right ionization energy increases because of
increased effective nuclear charge.
• Moving across a row from left to right ionization energy increases because of
increased effective nuclear charge.
Ionization energy (IE) is the energy necessary to
remove an electron from an atom, molecule or ion. IE is
usually used to mean the first IE: the energy required for
the removal of a single electron from a neutral atom or
molecule. The second IE is the removal of an electron
from a monovalent anion.
An electron is removed by a photon with a known
energy (E = hν), and the kinetic energy (KE) is
measured for the released electron.
Moving down a group, IE decreases because of
increased electron shielding. Moving across a row from
left to right, IE increases because of increased effective
nuclear charge.
There are exceptions to the general trends.
Electrons in higher energy orbitals are easier to remove
than electrons in lower energy orbitals.
It is easier to remove an electron from a 2p orbital than it
is to remove one from a 2s orbital.
It is easier to remove an electron if it is paired than if it is
unpaired.
Ionization energy (IE) is the energy necessary to
remove an electron from an atom, molecule or ion. IE is
usually used to mean the first IE: the energy required for
the removal of a single electron from a neutral atom or
molecule. The second IE is the removal of an electron
from a monovalent anion.
An electron is removed by a photon with a known
energy (E = hν), and the kinetic energy (KE) is
measured for the released electron.
Moving down a group, IE decreases because of
increased electron shielding. Moving across a row from
left to right, IE increases because of increased effective
nuclear charge.
There are exceptions to the general trends.
Electrons in higher energy orbitals are easier to remove
than electrons in lower energy orbitals.
It is easier to remove an electron from a 2p orbital than it
is to remove one from a 2s orbital.
It is easier to remove an electron if it is paired than if it is
unpaired.
Why does the second ionization energy roughly follow the same trend as the first ionization energy but is offset by one element?
The electron configuration is identical to the next lower element when the first electron is removed. (D)
In which of the following lists are the elements arranged in order of increasing ionization energies?
Fe, Co, Ni, Cu (A)
Which of the following is not a periodic trend?
Oxidation state (B)
Oxidation state is not a periodic trend. For some groups it remains constant throughout the group while in other groups it varies due to the electron configuration of the element.
Which of the following is used to describe the ionization energy for hydrogen?
Schrödinger equation (D)
The Schrödinger equation is used to calculate the energy of the electron(s) in an atom.
What happens to the ionization energy as the size of the nucleus increases?
It increases. (D)
The ionization energy increases as the nucleus increases because the nucleus exerts more and more attraction that serves to hold the electron in place within the atom. As the size of the nucleus increases, the attraction it exerts on the electrons increases.
How does the magnitude of the second ionization energy compare to the first ionization energy for an atom?
After the first electron is removed, the influence exerted by the nucleus increases which increases the second ionization energy. (A)
As electrons are removed from the valence shell, the attraction to the nucleus increases because of the decreased number of electrons. Each time an electron is removed, more energy is required to remove the next electron.
Which of the following transitions of electrons between orbitals results in the emission of energy?
3p to 3s (C)
Energy is released when electrons move from a higher energy orbital to a lower energy orbital as in moving from 3p to 3s.
Which of the follow explains why there is a difference in first ionization energy between nitrogen and oxygen?
Nitrogen has a more stable electron configuration (C)
Nitrogen has three electrons in its valence shell. Each of the electrons occupies one of the three orbitals in the 2p energy sublevel. This configuration of half-filled orbitals is more stable than all configurations except completely filled. Because there are only three orbitals in the 2p energy sublevel, oxygen has to double up electrons in one of the p orbitals. Because there are two electrons in one of the orbitals, it is easier to pull that electron out so, oxygen has a slightly lower ionization energy than nitrogen.
What is the total number of electrons that can be held in the 2p orbitals?
6 (D)
The 2p orbitals have space for three pairs or a total of six electrons.
What happens to the successive ionization energies as more and more electrons are removed?
The ionization energies continue to increase a relatively steady amount with each electron removed. (C)
The ionization energy continues to increase at a relatively steady amount. As an electron is removed, the amount of attraction that the nucleus exerts on the remaining electrons increases. When another electron is removed, the amount of attraction on each electron is increased by a similar amount. The ionization energy increases significantly however, when removing the first electron of any energy level.
