Answer:
Thumb
Explanation:
The direction of the magnetic field can be determined by using the right-hand rule. According to this rule, hold a current carrying wire in your right hand such that the thumb of the right-hand point in the direction of electric current. The curled finger gives the direction of the magnetic field.
Hence, the thumb shows the electric current.
Cuz their is two unpaired valency electrons in their elemental state or because they all have the same number of valency electrons
Hope it helps!