Which particles are responsible for the flow of current in conductors?

How many electrons constitute a total charge of $1 \ C$?

If $4.8 \text{ A}$ current is passed through an electrical appliance,then the number of electrons passing through it in $1 \text{ second}$ will be $......$

Which of the following materials has the highest number of free electrons?

What is the total electric charge on $100$ protons in Coulombs?

What is the frequency of $DC$ (in $Hz$)?