18 Questions
What is responsible for electrical conductance in metals?
Movement of electrons
Which factors affect electronic conductance in metals?
Nature and structure of the metal, number of valence electrons per atom, temperature
What did MacDiarmid, Heeger, and Shirakawa discover in 1977?
Polymerization of acetylene gas to produce polyacetylene
What properties do organic conducting polymers possess?
Metallic properties like conductivity and light weight
Why are organic conducting polymers much lighter than normal metals?
They are composed wholly of elements like carbon, hydrogen, and occasionally nitrogen, oxygen or sulfur
For their discovery of conducting polymers, who was awarded the Nobel Prize in Chemistry for the year 2000?
MacDiarmid, Heeger, and Shirakawa
What type of materials have conductivity between conductors and insulators?
Semiconductors
Which material is an example of a semiconductor?
Silicon
What is the conductivity of copper oxide (CuO) as per the table?
$3.5 \times 10^{-5} S m^{-1}$
Which type of material has very low conductivity and is known as insulators?
Glass
What type of materials are classified as conductors due to their high conductivity?
Copper
Which material has infinite conductivity by definition?
Superconductors
Why does the composition of a metallic conductor remain unchanged as electrons move through it?
The electrons enter at one end and exit through the other end.
What is the main difference in the mechanism of conductance between metallic conductors and semiconductors?
Metals conduct electricity through free electrons, while semiconductors have a more complex conductance mechanism.
Why does very pure water have low conductivity despite having small amounts of hydrogen and hydroxyl ions?
The ions in very pure water are not mobile enough to conduct electricity effectively.
What is the term used to describe the conductance of electricity by ions present in solutions?
Electrolytic conductance
Which of the following factors does NOT affect the conductivity of electrolytic (ionic) solutions?
Pressure applied to the solution
What can happen to the composition of an ionic solution when a direct current is passed through it over a prolonged period?
The composition can change due to electrochemical reactions.
Test your knowledge on superconductors, metallic conductance, and factors affecting electronic conductance through metals. Learn about the behavior of different materials at high and low temperatures.
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