Conduction should be the correct answer.
Average atomic mass listed for nitrogen in the periodic table is 14
Hope this helps!
Conduction: In the conduction, the heat is transferred from the hotter body to the colder body until the temperature on both bodies are equal.
In thermal equilibrium, there is no heat transfer as the heat is transferred till the temperature on the bodies are not same.
In the given problem, an iron bar at 200°C is placed in thermal contact with an identical iron bar at 120°C in an isolated system. After 30 minutes, the thermal equilibrium is attained. Then, the temperature on both iron bars are equal.Both iron bars are at 160°C in an isolated system.
But in an open system, the temperatures of the iron bars after 30 minutes would be less than 160°C. There will be heat lost to the surrounding. The room temperature is 25°C. There will be exchange of the heat occur between the iron bars and the surrounding. But It would take more than 30 minutes for both iron bars to reach 160°C because heat would be transferred less efficiently.
<span>The correct answer is neither attraction nor repulsion.</span>
<span>Kinetic Molecular Theory explains that gas particles are in constant motion and exhibit perfectly elastic collisions. The motion of gas particles is random, meaning that there are no attractive forces on each other or on their surroundings. When two particles collide, the total kinetic energy is conserved.</span>
I'm pretty sure that significant figures is just the amount of numbers there is. So, in this case I think the answer would be D. 5
