Noble gas configuration for Li : [He]2s¹
<h3>Further explanation
</h3>
In an atom, there are levels of energy in the shell and sub-shell
This energy level is expressed in the form of electron configurations.
Lithium with atomic number 3, then the electron configuration:
1s²2s¹
And for noble gas configuration or it can be called Condensed electron configurations :
[He]2s¹
Given :
A compound has a molar mass of 129 g/mol .
Empirical formula of compound is C₂H₅N .
To Find :
The molecular formula of the compound.
Solution :
Empirical mass of compound :

Now, n-factor is :

Multiplying each atom in the formula by 3 , we get :
Molecular Formula, C₆H₁₅N₃
Record observations, pose a question, create a test for an individual variable, test, come to a conclusion
Answer:
not 100% sure but I think it's unbalanced chemical