The slight error has been to use the prefix mono to name monocarbon.The compound she is most likely naming is:

.
As you see, the chemical formula has 1 atom of C, which is likely why she named it mono, and 4 atoms of Br.
The right name is carbon monobromide, i.e. you have to supress the prefix mono, as per IUPAC rules.
Answer:
From 00:11
Balance the Molecular Equation
From 01:35
Ions for the Complete Ionic Equation
From 03:04
Net Ionic EquationExplanation:
Answer: Electric energy
Explanation: Electrical energy is stored between plates in electric field
Is by turning a few seconds before