Who is the father of the periodic table?
Dmitri Mendeleev
What is the periodic law that Mendeleev proposed?
Properties of the elements are periodic (repeated/consistent) functions of atomic weight.
As we go from LEFT to RIGHT across a period, does atomic radius increase or decrease?
Decrease
As we go DOWN a family or group, does the atomic radius increase or decrease?
Increase
Why is it that when we go from left to right across a period, the atomic radius decreases?
Valence electrons are in the same energy level as we from left to right, but nuclear charge increases. This increase in Coloumbic attraction pulls the valence electrons closer to the positively charged nucleus, thus decreasing the atomic radius.
Why is that when we go down a group, the atomic radius increases?
As we go down a group, the valence electrons are located in HIGHER energy levels, further from the nucleus. There is a difference in energy levels.
What is the atomic radius?
Distance from the nucleus to the outermost energy level.
Are anions larger or smaller than their neutral atom?
Larger; The force of attraction decreases for all electrons because of the increased amount of the repulsion-repulsion behavior of the newly acquired electrons.
Are cations smaller or larger than their neutral atom?
Cations are smaller than the neutral atom because the force of attraction increases for remaining electrions. The loss of electrons allows the positively charged nucleus to better attract and pull in the few electrons that are left.
For what process is ionization energy measured?
Loss of an electron
Why is energy required for ionization energy?
To break the attractive force
How does Coulomb's Law explain why ionization energy increases across a period?
As we go across a period, the nuclear charge increases, so the force of attraction increase in strength, therefore, more energy is required to break the force.
How does Coulomb's law explain why ionization energy decreases as you go down a group?
As we go down a group, valence electrons are higher in energy level, farther from the nucleus, so force of attraction is less, therefore, less energy is required to remove electrons. Also a shielding effect by the core electrons that decreases the attract
How does the ionizaiton trend relate to the atomic radius trend?
Opposite
What is electron affinity?
Refers to the released energy that is measured when an electron adds to a gaseous atom.
As electron affinity goes from left to right, does increase or decrease?
Increase (becomes more negative)
As you go from top to bottom on the periodic table, what happens to electron affinity?
It decreases