Chemistry 1100 Ch 5

what happens when a hydrogen atom absorbs light?

the energy of the photon converts it from the ground state to an excited state, transferring an electron to an orbital larger and less stable

more charge binds the electron…

stronger and lowers the energy of the orbital making it more stable

what is ionization energy?

the energy required to remove one electron from an atom, (always positive, since losing one electron makes it less negative)

it is more difficult to remove an electron from a…

positively charged species

less electrons means…

a higher attraction

a nucleus is positive charged, while an electron is negatively charged when you multiply their charges what will their potential energy be?

negative

what happens to r and potential energy when oppositely charges get closer together?

r decreases (distance between the two central points), and potential energy decreases since it will be more negative. This means the electron becomes more stable and the attraction is stronger

What happens when two electrons have like charges?

their r decreases, while their E (potential energy) increases. Meaning the repulsion becomes stronger and the arrangement is less stable

describe the attraction between He+ and H

H has 1 proton, while He+ has 2 protons. Since He+ 2 protons it has a greater nuclear charge, meaning it will attract electrons more strongly. This also means it will take more effort to remove an electron from He+, it ionization energy will be higher

the total number of electrons in an atom will affect…

the energy levels and ionization energy

an electron in a multi electron atom is attracted to the nucleus but…

repelled by the other electrons

electron-electron repulsion____ the energies of the levels ____ the energy required to remove an electron

raises, reducing

the force an electron feels is dependent on…

the distance from the nucleus and the amount of charge

larger distance (higher energy level) means…

less attraction

higher charge on the nucleus means…

more attraction

what is screening

electron-electron repulsion, cancelling a portion of the attraction between the nucleus and the incoming electron

in screening, an electron feels…

a net attraction called an effective nuclear charge, Zeff

electrons are only screened by…

inner electrons, because smaller orbitals are more compact and screen other electrons more effectively

the higher the value of the quantum number n, the more that orbital is…

screened by electrons in smaller more stable orbitals

the higher the value of the quantum number L, the more…

that electrons in that orbital are screened from their nuclear charge by electrons in smaller, more stable orbitals

photoelectron spectroscopy…

gives us quantitative info about energies of atomic orbitals

what is Z eff?

an electrons net attraction

what is the Pauli exclusion principle?

each electron in an atom has a unique set of four quantum numbers, (n, l, ml and ms)

what is the Aufbau principle?

when we place electrons in orbitals starting with the lowest energy orbital following the Pauli exclusion principle

what are the maximum sub shell capacities for each orbital?

s= 2 electrons, p= 6 electrons, d= 10 electrons, f= 14 electrons

when is an electron spatially accessible?

when it occupies one of the largest orbitals of an atom

when is an electron energetically accessible?

when it occupies sone of the least stable occupied orbitals of an atom (Valance electrons)

in the first 40 elements what are the two exceptions to orbital filling

Cr and Cu

why are Cr and Cu exceptions of orbital filling normalities?

because of near-degenerate orbitals: orbitals with nearly the same energy.

for the electron configuration of transition metals cations, you…

first remove electrons from the highest energy orbital, with the highest n value

diamagnetic

if they are repelled by a strong magnet. occurs in substances in which the ions or atoms have paired electrons

paramagnetic

if they are attracted to a magnet, aligns itself in a magnetic field. usually weak. occurs in substances which the ions or atoms have unpaired electrons

ferromagnetic

strong paramagnetic materials ex. refrigerator magnets

isoelectronic

ions with the same number if electrons