What is the unit for speed ? for acceleration?

Speed - the rate of change of position. 
Speed = Distance / Time. 
Common units utilized for speed are meters per second (m/s) or miles per hour (mi/h). 

Velocity - the rate of change of position. 
Velocity = Displacement / Time. 
Common units utilized for velocity are meters per second (m/s) or miles per hour (mi/h). 

The main difference between speed and velocity is that speed is a scalar quantity (does not depend on direction) whereas velocity is a vector quantity (which does depend on direction). 

Acceleration - Change of velocity over time. 
Force = Mass x Acceleration. 
Acceleration = Force / Mass. 
Common used units of acceleration are meters per second squared (m/s^2). 

Hope that helped :)

An atom that has fewer electrons that protons is called a positive ion.