periodic trends

Question 1

effective nuclear charge

Answer 1

z* —-
net charge experienced by an electron resulting from a balance of the attractive forces of the nucleus and repulsive forces of other electrons —-
increases as you go left bc of shielding effect —
larger orbitals = electrons held less tightly

Question 2

aufbau principle

Answer 2

lower energy orbitals are filled first

Question 3

hund’s rule

Answer 3

degenerate orbitals (same energy) have to be filled with electrons until they are all have filled before pairing of electrons can occur

Question 4

pauli exclusion principle

Answer 4

indivual orbitals can only hold two electrons, each should have a different spin

Question 5

cations (Na equation)

Answer 5

atom loses electrons (positive charge)

Na –> Na+ + e-

Question 6

anions (F equations)

Answer 6

atoms gain electrons (negative charge)

F + e- –> F-

Question 7

isoelectronic series

Answer 7

ions create same number of electrons

Question 8

electron configuration exceptions

Answer 8

cr and cu

Question 9

diamagnetic substance

Answer 9

not attracted to magnetic substances — ions with paired electrons

Question 10

paramagnetic substance

Answer 10

attracted to magnetic substances —

ions with unpaired electrons

Question 11

bonding atomic radius

Answer 11

one half the distance between covalently bonded nucleui

Question 12

atomic radii trend

Answer 12

decreases from left to right because effective nuclear charge increases and electrons are held closer to nucleus —-
increases from top to bottom because there are more energy levels (n)

Question 13

ionization energy (what and general trends)

Answer 13

the amount of energy required to remove an electron from the ground state of a gaseous atom or ion —-
less energy down a group for 1st one because the valence electrons are further away from nucleus —-
increases across a period because zeff increases

Question 14

first and second ionization energy (equations with a)

Answer 14

requires more energy to remove each next electron (takes a leap after valence electrons)
A + energy –> A+ + e-
A+ + energty –> A2+ + e-

Question 15

exceptions to ionization energy trends

Answer 15

groups IIa and IIIa

electron further from nucleus is removed from p orbital rather than s orbital

Question 16

electron affinity (what and general trends)

Answer 16

energy charge when adding an electron to gaseous atom (delta ea H) -
ability to attract electrons
electron affinity became more exothermic from as you go right
increases across period
decrease down a group bc its farther from nucleus

Question 17

exceptions to electron affinity

Answer 17

groups 1 and 2: an added electron goes to p orbital and feels repulsions form s-electron because it is farther away —–
groups Iva and va: it has no empty orbitals so the extra electron goes to an already occupied orbital and creates a repulsion

Question 18

size of ion depends on…

ion size trend

Answer 18

nucleur charge, number of electrons, and orbital of electrons —–
increase down group bc n value increases

Question 19

cations and parent atoms

Answer 19

smaller than parent because the outermost energy level is removed and repulsions are reduced

Question 20

anions and parent atoms

Answer 20

larger than parent because electrons are added and repulsions are increased