Which compound contains ionic bonds? a
C6H12O6 (s)
b
CO2 (g)
c
HBr (g)
d
NaBr (s)

See explanation

Explanation:

Even though the image is missing here but i believe that the other pancakes are at different temperatures. If this is the case, the pancake at the highest temperature will make the bottom pancake the warmest due to transfer of thermal energy.

The transfer of thermal energy between the hotter pancake and the bottom pancake occurs by conduction. Conduction is a mode of transfer of thermal energy that occurs when the two bodies are in close contact with each other.

After they have been touching for a while, the temperature of the bottom pancake increases while the temperature of the top pancake decreases since thermal energy is being transferred from the top pancake to the bottom pancake.