Answers & Explanation:
#1: (C) molecules
Conduction is a form of heat transmission where atoms(that are part of a metal molecule), when heated, become agitated and collide with other atoms, propagating heat from one to another.
Example: When we cook something and leave the spoon in contact with the hot pan, the spoon becomes hot too.
#2 (A) by convection
Thermal convection is one of the forms of heat propagation that occurs in liquids and gases.
It is called this because heat transmission occurs through circular convection currents that form due to the different density between fluids. The density changes when the temperature varies.
Example: When we heat a pan on the stove, this process creates convection currents where the water near the fire becomes less dense and rises, while the cold water becomes denser and falls
#3 (C) radiation
Thermal radiation occurs through the emission of electromagnetic waves, and therefore does not need a material (solid, liquid or gas) to happen.
In this type of process, part of the thermal energy of the bodies is converted into electromagnetic energy and also in the opposite way.
Example: Imagine a microwave oven, this appliance heats food without contact with it, and unlike the ordinary oven, it does not need to heat the air. While the food is heated there is a microwave emission that increases its thermal energy, increasing the temperature.
