Iron and nickel are the elements most similar to cobalt
<span>This law means that when one object exerts force on another, the same amount of force is exerted on the initial object, but in the opposite reaction. For example, when a billiard ball strikes another ball, the second ball is propelled forward. Simultaneously, the momentum of the first ball is slowed or stopped by opposing force. The amount that the first object is affected by the opposing force depends on the mass and motion of the second object.</span>
Group 17 is the second column from the right in the periodic table and contains six elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (As), and (Ts). Astatine and are radioactive elements with very short half-lives and thus do not occur naturally.
Explanation:
In the given situation two forces are working. These are:
1) Electric force (acting in the downward direction) = qE
2) weight (acting in the downward direction) = mg
Therefore, work done by all the forces = change in kinetic energy
Hence,
It is known that the weight of electron is far less compared to electric force. Therefore, we can neglect the weight and the above equation will be as follows.

v = 
= 592999 m/s
Since, the electron is travelling downwards it means that it looses the potential energy.