Question

why can heat be conducted through solids liquid and gases but not through vaccum

Answer 1

Heat needs a medium to propagate and in solid liquid and gases there are molecules which help in propagation... The molecules absorb the heat energy and come to an excited stage but are not stable and hence it again gives away the energy and it is absorbed by some other molecule ,this way it is propagated but in case of vacuum there are no particles present hence there is no absorption of energy.
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