This is for physical science, pls dont use g00gIe
What is a vector?

A vector is an object that has both a magnitude and a direction. We can picture a vector as a directed line segment, whose length is the magnitude of the vector and with an arrow indicating the direction.

~iwa-chan

answer; /// i do believe that the correct answer is (c)nuclear bond

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.