Chemistry
The open "Sigrees" or coal stoves often require fanning to sustain burning because of

Accumulation of smoke and dust over the sigrees
Tendency of carbon dioxide to form a layer along with dust smoke
Lack of oxygen in the surroundings of sigrees
Interrupted release of moisture from the material

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Chemistry
The lustre of the metals is because of

High density, due to closed packing of atoms
Reflection of light due to the presence of free electrons
High polish
Absorption of light due to the presence of cavities

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