Which of the following is not a vector quantity?

1. Analyze the question You are asked to find the quantity that is not a vector. So you need to know the difference between vectors and scalars.

2. Explain the concept

• Vector quantity: has both magnitude and direction (e.g. velocity, force, displacement, momentum, acceleration, weight).
• Scalar quantity: has magnitude only, with no direction (e.g. mass, time, speed, distance, energy, temperature).

3. Go through each option

• A. Momentum: momentum = mass × velocity. Velocity is a vector, so momentum has a direction. It is a vector.
• B. Force: a push or pull always acts in a particular direction (e.g. 10 N upward). It is a vector.
• C. Temperature: if a room is at 30 °C, you cannot give that a direction. It only has a magnitude. It is a scalar.
• D. Displacement: this is distance in a specified direction (e.g. 5 m north). It is a vector.

4. Answer The only quantity that is not a vector is temperature, so the answer is C.

5. Exam tip Remember the scalar pairs that JAMB loves to test:

• Distance is scalar, while displacement is a vector.
• Speed is scalar, while velocity is a vector.

Also, scalars to memorize: mass, time, temperature, energy, work, power, density, speed, distance. Anything with "direction" in its everyday use (push, pull, shift, move toward) is usually a vector.