Whats the difference between speed and velocity of an object

The difference between speed and velocity is that the speed is a scalar quantity which means that you can say that this object has a speed of x m/s but you don't have to define its direction
while the velocity is a vector quantity which means that you have to express the velocity by which it moves in x,y and z directions and its norm is the speed

B) erini just took the test and it is correct

It is either a  proton or a neutron im almost positive. hope this .