Page 13 - Curriculum Visions Dynamic Book

Hf see Hafnium; Hg see Mercury Holmium (Ho)
Element 67. It is a rare-earth metal (lanthanide) in the Periodic Table.
It is soft and easily worked. It is highly magnetic and only reacts in air slowly,
so that it does not tarnish readily.
Discovery
It was first identified in Stockholm in 1879 by the Swedish chemist T. Cleve.
Technology
It has few uses but is sometimes used in alloys.
Geology
Never found as a native element, but in monazite and gadolinite ores.
Biology
Holmium does not occur in living things.
often used in mixtures with oxygen for diving cylinders and prevents the ‘bends’. Speaking
after breathing an
atmosphere rich in helium results in a squeaky voice.That is the way deep- sea divers are heard speaking because their air cylinders are helium-rich.
 Helium is used to fill party balloons and modern airships because it is safer than using hydrogen. It has almost the same lifting power as hydrogen, but cannot catch fire. Of all the helium produced, 10% is used for lifting.
Key facts...
Name: holmium
Symbol: Ho
Atomic number: 67
Atomic weight: 164.9
Position in Periodic Table: inner transition
metal; period 6 (lanthanide series) State at room temperature: solid Colour: silvery-white
Density of solid: 8.78 g/cc
Melting point: 1,470°C
Boiling point: 2,720°C
Origin of name: named after Holmia, the Latin
name for the city of Stockholm
Shell pattern of electrons: 2–8–18–29–8–2
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