The correct answer is D. Nitrogen.
Metals are elements that are typically shiny, have a high melting point, and are good conductors of heat and electricity. Non-metals are elements that are typically dull, have a low melting point, and are poor conductors of heat and electricity.
Iron, aluminium, and zinc are all metals. They are all shiny, have a high melting point, and are good conductors of heat and electricity. Nitrogen is a non-metal. It is a dull gas with a low melting point and is a poor conductor of heat and electricity.
Here is a table that summarizes the properties of metals and non-metals:
| Property | Metal | Non-metal |
|—|—|—|
| Appearance | Shiny | Dull |
| Melting point | High | Low |
| Conductivity | Good | Poor |
I hope this helps! Let me know if you have any other questions.