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Oftentimes, it is not the complicated Science concepts, but instead, the simple ones that confuse us. Don’t you think so?
In today’s article, I will be discussing some basic terms and concepts from the topic of Materials that my students often misunderstand and apply incorrectly.
Let’s Get Started!
Are you able to accurately differentiate between the following terms?
Conductors of Heat
These are materials that allow heat to pass through them.
Good conductor: A good conductor of heat allows heat to pass through it QUICKLY.
Poor conductor: A poor conductor of heat allows heat to pass through it SLOWLY.
Better conductor: A better conductor of heat allows heat to pass through it FASTER.
Poorer conductor: A poorer conductor of heat allows heat to pass through it SLOWER.
Insulators of Heat
There is NO such term.
This is because heat will ALWAYS be able to pass through both matter and non-matter.
The only difference is how fast or how slow heat travels.
Conductors of Electricity
These are materials that allow electric current to be conducted through them.
Good conductor: A good conductor of electricity allows electric current to pass through it easily.
Poor conductor: A poor conductor of electricity does not allow electric current to pass through it easily.
Better conductor: A better conductor of electricity allows MORE electric current to pass through it.
Poorer conductor: A poorer conductor of electricity allows LESS electric current to pass through it.
Insulators of Electricity
These are materials that DO NOT allow electric current to pass through them.
Let’s Apply These Concepts On This Question
Source: Pei Hwa Presbyterian Primary School – 2017 P6 Science Preliminary Examination Paper [Q4]
If your answer is Option (1), you’d have chosen the same answer as half of my students.
Perhaps, Option (1) seemed to be the best possible answer amongst the 4 options to you, given that the ice cube was in the top half of the container where the cooler was.
Many of my students also shared with me that the black object and the air surrounding the ice cube, which are a poor conductors of heat, would not allow heat from the heater to be conducted to the ice cube.
Hence, the ice cube should remain as a solid as it would take a long time to melt.
Unfortunately, Option (1) is incorrect. In fact, certain parts of their (my students’) explanation above, do not even make sense!
Let me share with you why.
First of all, as mentioned previously in this article, a poor conductor of heat allows heat to pass through it slowly. It does not mean that heat from the heater will not be conducted to the ice cube at all!
Given that hot air rises and cold air sinks, the air that gained heat from the heater would become warmer and rise to the top of the container.
Thus, the air surrounding the ice cube would be warmer, causing the ice cubes to gain heat from the warmer surrounding air and melt.
Given that 3 hours is a long time, the ice would have melted completely. As such, the answer for this question is Option (2).
Nevertheless, let’s run through other two options:
Option (3): All the water escaped from the set-up.
It was mentioned that the tank was “completely sealed”.
Even if the ice has melted to form water and the water that dripped onto the heater has boiled to form steam, the steam would not be able to escape from the container.
Option (4): All the water was collected on the heater.
The water that collects on the heater would gain heat from the heater to boil and form steam.
Thus, it is not possible for water to have collected on the heater.
I hope this article has helped you to gain a better understanding of various terms used to describe some properties of materials, as well as how to analyse Heat-related questions.
Wishing you all the best in your revision for the upcoming Preliminary examinations!