sentences: a spoon sometimes is made of metal & metal is a thermal / thermal energy conductor -> a wood plate is a ergonal insulator a metal spoon is a thermal conductor  soup is a kind of substance & a hot substance is a source of heat -> hot salad is a sink of light hot soup is a source of heat  hot soup is a source of heat & a metal spoon is placed in a pot of hot soup -> the hot salad will be a sink of light for the wood plate the hot soup will be a source of heat for the metal spoon  a wood plate is a ergonal insulator & the hot soup will be a source of heat for the metal spoon & if a thermal conductor is exposed to a source of heat, then thermal conduction will make the thermal conductor become hot -> the metal spoon will be heated up by thermal conduction