Answer:
[tex]Unit\ Charge = -6\ units[/tex]
Step-by-step explanation:
Question is incomplete; However, the missing part of the question will most likely be to calculate the charges on each particle.
If that is the case;
[tex]Tota\l Charges = -42\ units[/tex]
We'll get the unit charge when we divide by 7.
This is so because, they all have the same charge.
[tex]Unit\ Charge = -42\ units/7[/tex]
[tex]Unit\ Charge = -6\ units[/tex]
Hence;
the unit charge is -6 units
