why are energy levels assigned negative values?

Question

I am refering to Bohr's theroem of hydrogen. He used a formula involving the "Rydberg constant". My question is why are energy levels assigned negative values is it because the negative sign says that the energy is giving off to the surroundings? or is it because the negative sign signifying that the energy of the electron in the atom is lower than the energy of a free electron? Thanks for helping

Answer 1

Negative energy can refer to several concepts:

* Negative rest energy, which corresponds to negative mass, which has many unusual physical consequences.
* Energy in any system below the conventionally-defined ground state. Examples are positrons under the dirac sea model of electron behavior, and the region of reduced vacuum energy associated with the Casimir effect. This type of effect typically occurs under exotic or unexpected conditions, as the definition of the ground state is usually chosen because it is the state of lowest expected energy within a system.
* Energy in any system below an arbitrarily defined zero level. Examples include electron potential energy within an atom under the Bohr model of atomic structure, and gravitational potential energy in Newton's model of gravity.

Answer 2

If I have an electronic circuit that runs off of a 12 volt battery and I take a volt meter and measure the voltage across the battery, and the meter reads 12.3 volt. 12.3 volts is the voltage level of the battery. If I then connect the meter across a component in the circuit and the meter reads 7.35 volts, that is the voltage level across that particular circuit component. If I connect the leads of the meter across a circuit terminal and the meter reads zero volts, that too is a voltage level. Do you see how that works? Best regards

Answer 3

by negative it indicates that energy is given out to the surroundings; we are looking from the system's (i.e. the energy level) point of view