Scalar and Vector quantities
Scalar Quantity
A scalar quantity is a quantity which has magnitude (size) but no specific direction. It is completely described by a numerical value and an appropriate unit. Examples of scalar quantities are mass (e.g. 500 kg) and temperature (e.g. 100°C).
Scalar quantities change when the magnitude (size) changes.
Vector Quantity
A vector quantity is a quantity which has both magnitude (size) and a specific direction. Force is an example of a vector quantity because it is only completely defined by stating the size of the force and the direction in which it acts.
Vector quantities change when their:
 Magnitude (size) changes
 Direction changes
 Magnitude (size) and direction changes.
SCALAR QUANTITY magnitude (size) only 
VECTOR QUANTITY magnitude (size) and a specific direction 

Distance Distance is a measure of how far an object moves, e.g. 100 meters. 
Displacement Displacement is the distance travelled in a particular direction from a specified point, e.g. 100 meters south east. 
Speed Speed is a measure of how fast an object is moving, e.g. 100 km/h 
Velocity Velocity is the speed in a stated direction, e.g. 100 km/h south east. 
Mass Mass is a measure of the amount of matter in an object, e.g. 100 kg. 
Weight Weight is the force by which the earth attracts a body towards its centre, e.g. 10,000 Newtons. 
Acceleration Acceleration is the rate of change of velocity in a stated direction, e.g. 3 m/s^{2} to the left. 

Force Force is a push or a pull in a particular direction, e.g. a frictional force of 10 N to the right tells us it is in the opposite direction to the motion of an object. 

Momentum Momentum is the product of mass and velocity; and the direction of the momentum is stated by the direction given by the velocity. 

Energy Energy is the ability to do work. This only requires a numerical value with its unit to define it. For example, the electric kettle transferred 2000 Joules of energy. 