one every 8 feet
No point on a countertop can be more than 24 inches from a receptacle per NEC 210.52. They have to be GFCI outlets per NEC 210.8.
For a home, to calculate the amount of receptacle outlets on a 15 amp circuit, each receptacle outlet should be calculated as not drawing more than one amp each.
The very first outlet in the circuit has a break, probably where the wires enter the receptacle.
There is no electrical code rule that prevents the installation of an electrical receptacle below a mirror.
Check on the back of the receptacle. There should be a symbol Cu/Al. This means that the receptacle is approved for both copper and aluminium conductors to be used on it. If it does not have the Al symbol on the back it means that this devices is not approved for use with aluminium conductors.
The strap or yoke on a duplex grounding type receptacle is the metal component that connects the two outlets together. It serves as the common connection point for the ground wires in the receptacle to ensure proper grounding.
To properly wire a split wired receptacle in your home, you will need to connect the hot wires to the brass screws on the receptacle and the neutral wires to the silver screws. Make sure to break the tab connecting the two brass screws to separate the top and bottom outlets. It's important to turn off the power before working on the receptacle to avoid any accidents.
The receptacle is usually 12" to center and a distance radius of six feet between outlets along the wall.
A split receptacle is an electrical outlet that has two separate outlets on the same device, each with its own power source. This allows you to plug in two devices independently. In contrast, a standard electrical outlet has only one outlet.
A #14 copper wire rated at 15 amps is the minimum size wire for a 15 amp receptacle.
That depends where you are. In north America the outlets are nominally 110 volts. I have tested many homes and find them actually from 105 to as much as 127 volts
The exception to the minimum branch-circuit wire size that can be installed in a dwelling is for load centers in dwelling units where the branch circuits supply 15-amp or 20-amp receptacle outlets and are protected by a 20-ampere overcurrent device.