ch 8 Flashcards
What is the Pauli Exclusion Principal?
No two electrons in an atom can have the same four quantum numbers, this is why ms is either 1/2 or -1/2, each orbital can only have 2 electrons so these opposite spins allow the Pauli Exclusion principal to make sense
Why are hydrogen atom sublevels not spilt?
Since hydrogen has empty sublevels, its energies are degenerate (equal). Orbitals in multi-electron atoms go through penetration and shielding which affects their energy levels and results in the splitting.
In general, the lower the l value, the lower the energy
What does Coulombs law state about particles with the same charge?
The potential energy is positive and decreases as the particles get farther apart. This is because they repel eachother
What does Coulomb’s law say about particles with the opposite charge?
The potential energy is negative and it becomes more negative as they get closer together
What does Coulomb’s law say about the magnitude?
As the charges of the particles increase, the magnitude of their interaction increases as well
When do electrons get excited and how does this affect their energy level?
When an electron absorbs a photon or bumps into a nearby atom or particle, it becomes excited, therefore raising its energy level to a higher principal quantum number
What is the effective nuclear charge (Zeff) and how does it display across a row?
The effective nuclear charge is the overall net charge that the outermost electrons experience. They are affected by the shielding of core electrons and the penetration of certain oribitals
The effective nuclear charge increases across a row due to the increasing number of protons and electrons. The valence electrons do not shield each other, so the larger amount of protons increases the force felt by the valence electrons. This makes the radius smaller as well
what are the trends for atomic radius?
As we move down a column, the atomic radius increases. As we move down a row, the principal energy level increases as well, meaning the valence electrons occupy larger orbitals, thereby causing a larger radius.
As we move across a column the atomic radius decreases. The radius across a row is determined by the inner pull experienced by the valence electrons from the nucleus. Since the effective nuclear charge increases as we go across a row, the pull experienced by these electrons increases as well, meaning that they are more tightly held onto. This results in a smaller radius.
Describe the radii of the transition elements
They stay roughly constant across each row
How do cations and anions affect radius?
Cations are much smaller than their corresponding atoms
Anions are much greater than their corresponding atoms
What is ionization energy and how does the first and second energy differ?
It is the energy required to remove an electron from the atom or ion in the gaseous state, it is always positive
the first ionization energy is the energy required to remove the first electron
the second ionization energy is the energy required to remove the second electron
What are the trends in ionization energies?
The first ionization energy decreases as we move down a column since the n value increases and the electrons held in the outermost energy levels are held onto less tightly
The first ionization energy increases as we move across a row since the electrons experience a greater effective nuclear charge, meaning they are held onto more tightly
What causes a large jump in ionization energy
ionization energy increases uniformly with each successive removal of the outermost electron but it takes a large jump with the removal of the first core electron
What is electron affinity
It is the energy change associated with gaining an electron by the atom in the gaseous state.
Most columns do not exhibit a definite trend in affinity. Group 1A metals have a more positive affinity as we go down the column (it is less exothermic) since it requires less energy to
As we move to the right, the affinity becomes more negative
