Explain why you cannot charge one end of a steel rod and leave the other end uncharged

Electrons can be made to move from one object to another. However, protons do not move because they are tightly bound in the nuclei of atoms. Static charge occurs when electrons build up on an object. Static charge:

can only build up on objects which are insulators, eg plastic or wood

cannot build up on objects that act as conductors, eg metals

Conductors allow the electrons to flow away, forming an electric current.

When a static charge on an object is discharged, an electric current flows through the air. This can cause sparks. Lightning is an example of a large amount of static charge being discharged.