How could you be moving in one frame of reference but not in another?

That happens all the time.  The answer is:  One frame of reference
is moving inside the other one.

Example:

-- You're sitting still, comfortable in a soft seat, reading a book. 
In the frame of reference of the seat, you're not moving, and
neither is the book.

-- The soft seat is in Row-17 of the passenger jet you're flying
in, at 37,000 feet.  In the frame of reference of somebody on
the ground, you're moving at 500 miles per hour.

The charge of an ion with 55 protons and 52 electrons is +3. the reason is because protons are positive, and there are three more than the amount of negative electrons.