Atomic orbitals - part 1

Question 1

Atomic orbital

Answer 1

it is a wave-like function that describes the probability on where an electron lies in the atom

Question 2

orbitals have

Answer 2

different shapes

Question 3

why do orbitals have different shapes?

Question 4

each orbital can contain

Answer 4

two electrons

Question 5

why do hydrogen electrons have a higher energy than helium electrons .

Answer 5

the energy of the orbital will be different from the orbital for hydrogen because it has double the nuclear charge of hydrogen and the electrons are more strongly attracted to the nucleus.

Question 6

Hund’s rule

Answer 6

. An atom adopts the electronic configuration that has the greatest number of unpaired electrons in degenerate orbitals.

Question 7

Regions where an electron is most likely to be found are said to have

Answer 7

high electron density

Question 8

regions where an electron is unlikely to be

Answer 8

found have low electron density.

Question 9

the square of the orbital wavefunction gives

Answer 9

the electron density at any location

Question 10

the probability of finding an electron in a small volume V at any location

Answer 10

the square multiplied by the small volume that we are looking for.

Question 11

Pauli exclusion rule

Answer 11

no two electrons can have the same four quantum numbers

Question 12

aufbau principle

Answer 12

in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.

Question 13

constructively overlap

Answer 13

in phase

Question 14

destructively overlap

Answer 14

out of phase

Question 15

Principal Q.N. (N)

Answer 15

determines size and energy

Question 16

orbital angular
momentum l

Answer 16

Orbital type
(s, p, d, f etc.)

Question 17

Magnetic ml

Answer 17

Orientation of orbital

Question 18

s

Answer 18

spin quantum number s

Question 19

spin

Answer 19

The spin can adopt one of two orientations, distinguished by the ms =  ½ quantum nu

Question 20

same energy

Answer 20

degenerate

Question 21

as n increases

Answer 21

it is further away from the nucleus

Question 22

for h

Answer 22

For an H atom, different orbitals with the same value of n have the same energy

Question 23

RDF

Answer 23

show how the electron density varies with distance from the nucleus and are related to the
squares of the orbital wavefunctions #

Question 24

radial dependence R(r)

Question 25

Why is H degenerate ?

Answer 25

It’s only the interaction of multiple electrons in an atom like He, Li, Be, etc. that makes the different angular momenta wave functions differ in energy.

Question 26

Why is H degenerate ?

Answer 26

It’s only the interaction of multiple electrons in an atom like He, Li, Be, etc. that makes the different angular momenta wave functions differ in energy.

Question 27

Nodes

Answer 27

A wave function node occurs at points where the wave function is zero and changes signs.

Question 28

iso-surface plots

Answer 28

show the angular shape and the size of the orbital

Question 29

Instead we draw an iso-surface joining points of equal probability and

Answer 29

enclosing say 90% of the
electron density

Question 30

filling orbitals

Answer 30

The 2s orbital always fills before the 2p orbital because in atoms with more than one electron, the 2s orbital is lower in energy than 2p

Question 31

core electrons

Answer 31

we refer to the filled 1s orbital as a core orbital and the
1s electrons as core electrons.

Question 32

core electrons are not

Answer 32

involved in chemical bonding

Question 33

overlap

Answer 33

The RDFs show that a 2s electron has a greater
probability of penetrating through the 1s core than does
the 2p electron

Question 34

2p vs 2s

Answer 34

On average, a 2s electron feels a larger net positive
charge than a 2p electron and hence is lower in energy.
We say that the 2s electron feels a greater effective
nuclear charge (Zeff) than the 2p electro