chapter 7

Question 1

Pauli exclusion principle

Answer 1

no more than two electrons can be assigned to the same orbital. if there are two electrons in an orbital. they have opposite spins

Question 2

the aufbau principle

Answer 2

electrons are assigned to shells and sub- shell in order of increasing energy

Question 3

the two general rules used to predict the arrangements of electrons

Answer 3

• electrons are assigned to sub- shells in order of increasing n + l value
• for two subshells with the same N + l value, the electrons are first placed in the subshell with the lowest n value

Question 4

effective nuclear charge

Answer 4

the net charge experienced by a charged electron in a multielectron atom due to the attraction force of the nucleus and the repulsive force of the other electrons

Question 5

the trend with effective nuclear charge

Answer 5

it is greater for electrons closer to the nucleus,

Question 6

ground state electron configuration

Answer 6

electrons are arranged in shells, sub shells and orbitals i order to produce the lowest energy for isolated atoms of an element

Question 7

core electrons

Answer 7

electrons that are included in the noble gas configuration of an element ,are excluded when considering the chemistry of an atom.

Question 8

valence electrons

Answer 8

electrons beyond the core electrons, these determine the chemical properties of an element

Question 9

s block Elements

Answer 9

group 1A to 2A elements with their outermost electrons being on the s subshell

Question 10

p block elements

Answer 10

group 3A to 8A elements with their outermost electrons being in the p orbital

Question 11

hunds rule

Answer 11

the most stable arrangement of electron in a subshell is that with the maximum amount of unpaired electrons

Question 12

electron configuration of anions

Answer 12

one or more electron is added to the valence shell of a non-metal atom so that it has an electron configuration of the next noble gas

Question 13

electron configuration of cations

Answer 13

electrons are removed from the shell with the highest n. if there are multiple subshells within the nth shell, electrons are removed from the sub shell with the highest l value

Question 14

paramagnetic

Answer 14

elements and compounds with unpaired electrons that are attracted to the magnetic field

Question 15

diamagnetic

Answer 15

elements that have all their electrons paired and experience a sight re pulsion when exposed to a magnetic field

Question 16

transition elements

Answer 16

elements that have their outermost electrons in the d(n-1) sub shell

Question 17

lanthanides

Answer 17

elements that have their outermost electrons in the f(n-1) sub- shell

Question 18

what does the period indicate in terms of quantum numbers

Answer 18

the period indicates the number of shells/ energy levels

Question 19

what does the group number indicate in terms of electrons

Answer 19

the number of valence electrons

Question 20

Give a reason why orbitals don’t have the same energy

Answer 20

as the number of electrons increases, the repulsion between the electros increases. the energy of the electron increases the further away it is from the nucleus of the atom

Question 21

what do metals do when ionising

Answer 21

metals loose electrons when ionising and form cations, positive ions

Question 22

what do non metals do when ionising

Answer 22

non metals gain electrons when ionising and form anions, negative ions

Question 23

exceptions when it comes to ion configuration

Answer 23

Cr and Cu. the 3d sub- shells fill up first, making the atom more stable

Question 24

what is the ionisation trend when it comes to transition metals

Answer 24

the p and s subshells of the outermost energy levels will loose electrons before the d subshell

Question 25

atomic size

Answer 25

half the average distance between the centres of covalently bonded atoms

Question 26

give the Zeff trend on the periodic table

Answer 26

• Zeff increases when moving from left to right across a period
• zeff decreases as you move down a group

Question 27

give the atomic size trend

Answer 27

when moving across a period from left to right the atomic size decreases
when moving down a group the atomic size increases

Question 28

isoelectronic

Answer 28

elements that have the same number of electrons

Question 29

ionisation energy

Answer 29

the amount of energy required to remove an electron from an atom at gas phase

Question 30

give the ionisation energy and enthalpy change trend in the periodic table and electron affinity

Answer 30

• when moving across a period from left to right the ionisation energy and the enthalpy change and electron affinity increases
• when moving down a group the ionisation energy and enthalpy change and electron affinity decreases

Question 31

electron affinity

Answer 31

the amount of energy that is released when a single atom gains an electron at gaseous phase