Atomic number.
The atomic number is what defines the element.
Carbon is the one and only element to make a molecule organic.
You can't usually just use a single spectrum line to confirm the identity of an element because there are cases that the emission line id not clearly defined. When the emission line is very weak compared to surrounding noise, in which case the more datapoints you have to build up confidence for the existence of a particular emission spectra, the better.
Answer:
5 atoms
Explanation:
According to the law of conservation of mass, "matter is neither created nor destroyed in the cause of a chemical reaction".
We finish with what we start with in a chemical reaction. Although new species might form, the number of atoms on both sides of the expression will still be maintained.
All chemical reactions obey this law of conservation.
