Answer: a vector
Explanation:
A Vector is a physical quantiy that has can magnitude and direction. Examples of vectors are Velocity, acceleration, force, momentum etc
Now, since velocity is defined as the displacement experienced by an object in a specified direction, it is therefore correct to call velocity a vector
The answer is; Sodium (Na+) and Potassium (K+) Ions
These cations are pumped out of the cell by Na+-K+ transmembrane protein pumps leaving the inside of the cell electronegative in relation to the extracellular matrix. This membrane potential is significant especially for neurons. Depolarization of the membrane enables transmissions of an impulse along the neurons.