Final exam Flashcards
Effective nuclear charge and atomic size in transition elements
for the first two columns the trend is the same as that of main group elements, but after they remain approximately const. Cause when electrons are added in transition metals they go into the (n-1)d shell which counts as a shielding electron. This cancels out with the additional proton increase.
Why is the first IE always greater than the second IE?
Bcs when an atom looses an electron, it tries to hold on to the remaining electrons more.
Trends in ionization energy across the period
It increases when electrons increase within the same subshell but decrease when we begin to fill the next sub-shell (Be and B) or when subshells become more than half-full (N and O)
pairing causes an increase in repulsion.
NOTE always be careful when given to compare the IE of two elements. You must check the above first.
Electron affinity
atoms gaining electron’s change in energy is negative
- *large negative means bigger (non-metals)
- *small negative means smaller (metals)
Group I elements EA is a small negative and not zero bcs an extra electron would give a closed sub-shell. But for group II, it would be close to zero. and positive for nobel gases.
The naming of ionic compounds
We don’t use the prefix convention.
How many valence electrons does the silver metal have
1
**rem: stability.
Probability density vs radial probability distribution function
probability density: Indicates the area where an electron is likely to be found.
radial probability distribution function: gives the probability of finding an electron in a spherical shell of distance “dr” at a certain distance from the nucleus.
Trends in bond energy
stronger across the row, and weaker down the column
advantage of MOs over lewis structures and valence models
O2 is predicted by these models as diamagnetic which does not much the experimental observation, while MOs show it as paramagnetic.
Dihedral angle
Angle btn two intersecting planes
Difference btn electronegativity and electron affinity
Electronegativity is defined as the chemical ability of an atom to attract an electron. … Electron affinity is defined as the amount of energy liberated when a molecule or neutral atom acquires an electron from outside.
Surface tension, viscosity and their relation
The energy required to increase the surface area by a unit amount is called surface tension.
surface tension is directly proportional to viscosity (resistance of flow).
