1A cаlоrie is the аmоunt оf heаt required to raise the temperature of a kilogram (about a quart) of water one degree Celsius. 2To determine the number of calories in a portion of food, a technician uses a device called a bomb calorimeter. 3This device has a chamber that rests in a container of water. 4The food is placed in this chamber, which is [Transition1] filled with oxygen under high pressure. 5Next, the food is set on fire. 6 [Transition2] it burns, it gives off heat, and the temperature of the water in the container rises. 7 [Transition3], the total rise in temperature is measured, giving the calorie content of the food.