(a)[1]
State the principal process by which thermal energy moves to the air throughout the room.
(b(i))[4]
Calculate the time required for this heater to increase the temperature of the air in the room from $8.0^{\circ}$C to $15.0^{\circ}$C.
(b(ii))[2]
State two reasons why the time found in (b)(i) is less than the actual time needed to raise the temperature of the air in the room from $8.0^{\circ}$C to $15.0^{\circ}$C.