Scientists in a laboratory were working with insulin, a protein often used to treat diabetes. They left two identical vials of insulin in different places. This table shows how the temperature of each vial changed over 15minutes.

Question

Vial Initial temperature (°C) Final temperature (°C)
Vial on the counter 2.5 5.9
Vial in the refrigerator 2.5 4.0
during this time, thermal energy was transferred from ? to ?
A. the surroundings... each vial
B. each vial...the surroundings

Answer 1

Thermal energy transfer can be understood in terms of heat exchange between a system (in this case, the vials of insulin) and their surroundings.

In the scenario given:

• The vial on the counter experienced a temperature increase from 2.5 °C to 5.9 °C, which indicates that it absorbed thermal energy from the surrounding environment (the warmer surroundings).
• The vial in the refrigerator experienced a smaller increase in temperature, from 2.5 °C to 4.0 °C, but still reflects a slight gain in thermal energy compared to its initial temperature.

Since both vials ended up absorbing heat from their surroundings, the correct option to describe the transfer of thermal energy would be:

A. the surroundings... each vial

The surroundings provided heat to each vial, causing them to increase in temperature.