Question

Electronic energy is negative because:
A. Electron has negative charge
B. Energy is zero near the nucleus and decreases as the distance from the nucleus increases
C. Energy is zero at infinite distance from the nucleus and decreases as the electron comes towards the nucleus.
D. These are interelectronic repulsions

Answer 1

Hint- In order to find the reason behind the negative electronic energy, first we will see the reason for energy to be positive or negative. Then we will compare the properties of electronic energy if it matches with that of the positive one or negative one.

Complete answer:
Formula used- ${E_n} = - {R_H}\left( {\dfrac{1}{{{n^2}}}} \right)$
Negative Electronic energy for hydrogen atom means that the energy released by the atom and it states that the hydrogen atom is displaced from higher energy orbit to lower energy orbit.
Or we can see this way also
This negative sign means the electron's energy in the atom is smaller than that of a free electron at rest. A free electron at rest is an electron infinitely far from the nucleus and the energy value of zero is given.
The most negative energy value is given by n=1 which corresponds to the most stable orbital and that is the Ground State.
${E_n} = - {R_H}\left( {\dfrac{1}{{{n^2}}}} \right)$
If $n = \infty $ then in the equation then ${E_\infty } = 0$ . As the electron gets closer to the nucleus (as n decreases), ${E_n}$ becomes larger in absolute value and more and more negative.
Hence, electronic energy is negative because energy is zero at infinite distance from the nucleus and decreases as the electron comes towards the nucleus.

So, the correct answer is option C.

Note- Electronic energy is also a curious feature in Hamiltonian mechanics, however, as you rightly pointed out, it does not require the contribution of the fixed nuclei's repulsions (which has little to do with electrons). But sometimes the total energy for a particular nuclear configuration (one that includes the above-mentioned contribution to interactions) is still (incorrectly) called "electronic energy" whereas only an own value of Hamiltonian electronic energy is called "pure electronic energy".