Module 1+2+3 Flashcards
(136 cards)
what does the term ‘lanthanides’ refer to
elements from Ce-Lu
what does the term ‘lanthanoids’ refer to
elements from La-Lu
what does the term ‘rare earths’ refer to
elements from La-Lu, Sc and Y
what does the term ‘actinides’ refer to
elements from Th-Lr
what does the term ‘actinoids’ refer to
elements from Ac-Lr
what are 2 early applications of the f-elements
gas mantle pyrophoric alloy (lighter flint)
what compound was found in a gas mantle and what did it do
CeO2
coverted light from gas lamp to heat - significantly brighter
what are 3 fields of use for lanthanoids
magnetic
optical
materials
what applications do lanthanoids have in magnetics
rare earth magnets (Nd) - used in wind turbines
MRI contrast agents
what applications do lanthanoids have in the optical field
security inks
lasers
lighting
what applications do lanthanoids have in materials
can form specialist alloys
what are 2 key applications of actinoids
nuclear power (235U) long life batteries (238Pu)
which are the 3 most abundant lanthanoids
La, Ce, Nd
which is the only lanthanoid not found in nature and why
Pm - radioactive
what 2 common elements are less abundant than lanthanoids
iodine
mercury
what are the 2 main mineral structures of lanthanoid sources
LnFCO3 - Bastnaesite
LnPO4 - Monazite
what are the top 4 locations with reserves and what percentage do they hold of rare earths
china 1/3
vietnam 1/6
brazil 1/6
russia 1/6
where are 97% of rare earths produced
china
elements above what atomic number and element are radioactive
83 (Bismuth)
how does the abundance of actinoids compare to lanthanoids
much lower
which are the 2 actinoids that exist in more than trace amounts
U 2.4 ppm
Th 12 ppm
what is the uranium decay series
235U - 231Th - 231Pa - 227Ac — 207Pb
what % of U is 235U
0.7%
what is the synthetic route of Ac from Ra
226Ra - 227Ra - 227Ac