electronic structure

Question 1

what is meant by Pauli’s exclusion principle?

Answer 1

no two electrons in an atom have the same four quantum numbers

Question 2

what is meant by Hund’s rule?

Answer 2

electrons fill orbitals singly first until all orbitals of the same energy are filled

orbitals are filled such that the lowest energy state is maintained

Question 3

what are the general rules of electron notation?

Answer 3

1. fill the lowest energy orbitals first
2. no two electrons can have the same quantum number - electrons have opposite spin
3. opposing spin is filled before moving to the next orbital

Question 4

what is the consequence of unpaired electrons in an orbital?

Answer 4

generation of magnetic field

Question 5

how can the outer shell electrons be identified from the periodic table?

Answer 5

row or period number gives the ‘n’ of the element

Question 6

what are the ‘s’ block elements and what does this mean?

Answer 6

first two columns of the periodic table and helium

the outer shell at ground state is a s sub shell - maximum of two electrons

Question 7

what are the ‘p’ block elements and what does this mean?

Answer 7

13th to 18th columns of the periodic table

outer shell at ground state has a p sub shell - max 6 electrons

Question 8

how many electrons can a d subshell have?

Answer 8

10

Question 9

how many electrons can an f subshell have?

Answer 9

14

Question 10

what are transition metals?

Answer 10

elements in columns 3 to 12 which have a partially filled d subshell

Question 11

why do some transition metals form coloured solutions?

Answer 11

transition energies of the d subshell electrons

Question 12

what is meant by ionisation energy?

Answer 12

the energy required to remove an electron from a gaseous atom or ion

Question 13

what is meant by first ionisation energy?

Answer 13

energy required to remove one of the first outermost electrons from an atom in its gaseous state

Question 14

what happens to first ionisation energy within a period/group?

Answer 14

increases from left to right (period)

decreases from top to bottom (group)

Question 15

what is the second ionisation energy?

Answer 15

energy required to remove a second valence electron from an ion

Question 16

what is electron affinity?

Answer 16

the ability of an atom to accept an electron. the stronger the attraction of a nucleus, the greater the electron affinity.

Question 17

what is the general trend regarding electron affinity within the periodic table?

Answer 17

more negative left _> right across a period

Question 18

what happens to the atomic radius across a period?

Answer 18

decreases from left to right - nuclear charge increases as the number of protons in an atom increases

increases moving down a group due to electron shielding

Question 19

what is meant by electronegativity?

Answer 19

the ability of an atom to pull or repel an electron when engaged in a bond

the greater the electronegativity of an atom, the greater its attraction for bonding electrons

Question 20

what determines bond strength?

Answer 20

bond strength is inversely proportional to bond length

Question 21

what are the general characteristics of metals?

Answer 21

hard and shiny
3 or less valence electrons
form cations by losing electrons
good conductors of heat and electricity

Question 22

what are the general characteristics of non metals?

Answer 22

gases, dull/brittle solids
5 or more valence electrons
form anions by gaining electrons
poor conductors of heat and electrons

Question 23

what are the general characteristics of metalloids?

Answer 23

3-7 valence electrons
form pos or neg ions
conduct okay - not as good as metals