Question

A piece of paper can be lighted by using a matchstick but not a log of wood. explain

Answer 1

the reason is hidden in the ignition temperature paper has less ignition temperature than wood thus burn faster

Answer 2

A piece of paper has a low ignition temperature, so a burning stick turns out to be sufficient heat to achieve the ignition temperature of the piece of paper, so that a stick is simply lightweight a piece of paper. However, a log of wood contains a high ignition temperature, which can not be obtained by the small amount of warmth produced by the burning stick. So, a burning stick cannot light-weight a log of wood directly.