Lecture 9

Question 1

core electrons

Answer 1

inner electrons
held tightly to the nucleus
don’t take part in bonding

Question 2

valence electrons

Answer 2

outer shell electrons
held less tightly due to shielding
participate in bonding

Question 3

photoemission spectroscopy

Answer 3

different variations: incident wavelength, method of analysis
measures the energy of ejected electrons
a surface analysis technique because light only penetrates into the material a few nm
non destructive, sensitive, trace analysis, high resolution

Question 4

XPS

Answer 4

x-ray photoelectron spectroscopy
targets core electrons
high energy

Question 5

UPS

Answer 5

ultraviolet photoelectron spectroscopy
probes valence electrons and chemical bonding

Question 6

basic principle

Answer 6

check notes

Question 7

real spectra

Answer 7

specific values of binding energy (where the peaks appear)
depending on a specific atom, used in peak assignment
used to obtain quantitative information about ratio of different elements

Question 8

case study 1

Answer 8

chemical analysis of fingerprints

Question 9

case study 2

Answer 9

forgery

Question 10

case study 3

Answer 10

AAS applications, quality control

Question 11

covalent bonding

Answer 11

e- shared between atoms
result of wave interference
valence electrons are held tightly and close to nucleus
close overlap, short range, directional

Question 12

hydrogen molecule

Answer 12

waves of atomic orbital
look at wave diagram in notes