Nitrogen: Non- metal = they are poor conductors of heat and electricity, they are brittle solids, not ductile in their solid state - they cannot be rolled into wires or pounded into sheets. They are usually dull and therefore show no metallic luster and they do not reflect light. They also have a low density.
Aluminium: Metal= Offers a rare combination of valuable properties. It is one of the lightest metals in the world: it's almost three times lighter than iron but it's also very strong, extremely flexible and corrosion resistant because its surface is always covered in an extremely thin and yet very strong layer of oxide film. It doesn't magnetise, it's a great electricity conductor and forms alloys with practically all other metals.
The correct thing to do in this case would be to <u>repeat the experiment.</u>
The scientist would need to repeat the experiment in order to double-check the accuracy. If the accuracy is indeed doubtful, he/she can be able to trace the source of the error by repeating the experiment.
