heat transfer

Question 1

conduction

Answer 1

when heat is travelled through solid materials such as metals and food
heat is conducted from molecule to molecule in a liquid of solid. for example when a gas flame warms the base of a metal saucepan, heat is conducted around the pan, the heat will then conduct into food and the food will cook

• metals conduct quickly in cooking pans , cooking utensils, steel and aluminium
  water is a good conductor
  plastics are poor conductors

Question 3

convection

Answer 3

heat travels through air or water
movement of heat in water or in air is called convection current
in ovens, convection happens because hot air will rise the top shelf ( top part ) and coolest part is the bottom shelf, where the fan circulates the heat and keeps all shelves the same temperature

• eg of convection : boiling, baking, poaching, steaming

Question 4

radiation

Answer 4

when heat rays directly warm and cook food
heat travels from one place to another
food that is grilled or toasted is cooked by radiation
requires a source of heat eg barbecue or grill

Question 5

convection current

Answer 5

movement of heat in water or air