Page 16 - Curriculum Visions Dynamic Book

I see Iodine
Indium (In)
Element 49.A rare silvery-white metal belonging to group 3 (the boron group) in the Periodic Table.
It is very soft and can easily be made to change shape. Pure indium ‘screams’ when it is bent. Indium will wet glass.
Discovery
Discovered in Germany in 1863 by Ferdinand Reich and Theodor Richter, using an instrument called a spectrometer, which analyses the unique range of colour given
off by each element.
Technology
Indium is used in making electronic components such as transistors, rectifiers, thermistors, and photoconductors. It is also used in low-melting-point alloys.An alloy of 24% indium and 76% gallium is liquid at room temperature. It is also part of engine bearings to help oil stick to metal. Hermetic seals between glass and other materials can be made from
it. Indium can be plated onto metal, and it will evaporate and then condense on glass, producing highly reflective mirrors. Such mirrors resist corrosion better than silver.
Geology
Indium is not found as the native element; it mainly occurs in iron, lead, copper and zinc ores. Indium
is therefore recovered as a by-product of refining these more common metals. Indium is as abundant as silver, being 63rd most common of the elements in the Earth’s surface rocks.
Biology
Indium is not found in living things but is not thought to be especially harmful.
Key facts...
Name: indium
Symbol: In
Atomic number: 49
Atomic weight: 114.82
Position in Periodic Table: group 3 (13)
(boron group); period 5
State at room temperature: solid Colour: silvery-white
Density of solid: 7.31 g/cc
Melting point: 156.6°C
Boiling point: 2,080°C
Origin of name: named after the indigo-
coloured line in its atomic spectrum Shell pattern of electrons: 2–8–18–18–3
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