Rows of elements are called periods. The period number<span> of an element signifies the highest unexcited energy level for an electron in that element.
</span>Columns of elements help define element groups<span>. </span>Elements within a group share<span> several common properties. Groups are elements have the same outer electron arrangement.</span>
You should be checking your gas appliances every year, it should always be a qualified technician.
What are the variables you have? I can't answer if I don't know? Haha. :)
Hello!
Elements are made up of atoms, and elements combine to make compounds. Compounds are made up of molecules, and molecules are made up of atoms.
Nitrogen is an element. It could be made up of one or many atoms. A mixture is made up of compounds, so it is not the answer.
Molecules and compounds are made up of different atoms and elements, but nitrogen is not a molecule or a compound.
There is such a thing as a nitrogen atom, though.
Therefore, your answer would be 2) Atom.
I hope this helps!
