A scientist designed a foam container to help keep frozen foods from melting. Which best explains how the foam works?

A scientist designed a foam container to help keep frozen foods from melting. Which best explains how the foam works?

• A. It reduces the amount of thermal energy that is transferred from inside to outside the container.
• B. It removes thermal energy from the air inside the container.
• C. It removes thermal energy from the frozen foods inside the container.
• D. It reduces the amount of thermal energy that is transferred from outside to inside the container.

Answer: (D)

Insulation slows heat transfer. The foam has many tiny air pockets, which have very low thermal conductivity, so heat from the warm surroundings moves into the container much more slowly. That keeps the interior colder longer, preventing the frozen foods from melting. The foam isn’t removing energy from inside or inside air; it’s reducing the rate at which heat enters from outside, which is the key to keeping foods frozen.

Insulation slows heat transfer. The foam has many tiny air pockets, which have very low thermal conductivity, so heat from the warm surroundings moves into the container much more slowly. That keeps the interior colder longer, preventing the frozen foods from melting. The foam isn’t removing energy from inside or inside air; it’s reducing the rate at which heat enters from outside, which is the key to keeping foods frozen.