A negative test charge will accelerate toward regions of electric potential and electric potential energy.

Choose the appropriate answer combination to fill in the blanks correctly.

higher; higher
higher; lower
lower; higher
lower; lower

higher and lower

Explanation:

 charge in an electric field will experience a force in the direction of decreasing potential energy. Since the electric potential energy of a negative charge is equal to the charge times the electric potential the direction of decreasing electric potential energy is the direction of increasing electric potential.

a.   mass number from atomic number