[restuip]

Ok , Hi everyone,
i've doing research with salt, but i have no idea (another HW).
the first experiment, i heat the salt and it's changes color into brown.
the second one, nothing happen

are someone can lecture me ?

[ATMyller]

What salt was it? NaCl or something else? Was the pot you heated the salt in clean, if not the first colour change could be due to contaminants mixing with the salt. e.g. frying pans can be cleaned by heating some NaCl on them.
The lack of brown colour in the second heating is most likely caused by the first heating that removed all the dirt from the heating pot.

[restuip]

yep salt is (NaCl)
, woow , today i do the experiment again, and yep the color is from the frying pan

but , i realize my fire getting bigger by itself, while heating the salt.
Any ideas?

[vmelkon]

It gives the appearance of getting bigger because the flame carries some of the sodium and chlorine and excites the atoms. Sodium emits its yellow light. I don't know about chlorine but probably it emits its own emission lines.