Answer:
Explanation:
exothermic reactions involve release of heat whereas endothermic reaction involve absorption of heat.
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.
It is 4/10 of moles is this ane halp?
Mass number is equal to the number of protons plus the number of neutrons in a nucleus of an atom