The transfer or movement of heat between two objects that are touching is

Conduction is the direct transfer of heat between two objects in contact with each other, or through an object in contact with both of the other objects.

Explanation: When you put your spoon in a cup of hot coffee, the spoon heats up.

the solar system used to have much dust particles option no d

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.