We don’t have a definitive answer to the exact matter-energy interaction. Therefore, we are unable to answer your question at a higher abstraction level, but detailed enough and accepted enough for an examination.
Circuits with conductors allow electricity to flow. Conductors that are commonly used include metals. The conductor of the circuit is any metal wire that forms it.
Fundamentally, the metal conductor wire is made up of atoms that have electrons. At a macro level, metals show what is known as the “Sea of Electrons” behavior. This means that electrons at the outermost levels of atoms are not bound to nuclear attraction and can move freely between atoms.
This means that there is a path of low resistance, literally, to allow electrons to flow through the conductor.
Let me answer your question.
1. The metal conductor is what connects the circuit to the electrons.
2. Matter is electrons. They cannot be created in the lifetime of an electric circuit. The discussion about the creation of electrons leads us to discuss the creation of matter in the realm particle physics, and not current electricity.
3. They move around in the circuit while being untethered to the conducting metal nuclei. Their movement is caused by the Voltage applied across the conductor’s ends.
Next, there’s a more interesting question: What exactly is Voltage?
This leads us to the source for the electric current. It is a battery. A battery can be described as two distinct bunches or quantities of electrons that are physically separated at the ends of a cell. Because it is more negatively charged, the end with more electrons will be called the -. The end with fewer electrons is the + end. It’s also more positively charged.
The natural tendency for electrons to level out is the same as that of water levels. When two water levels are connected at different heights, they tend to level out their height differences. This “height” can be compared to the “Electric potential”. Therefore, electrons at the negative end of a battery look to flow towards the positive side and neutralize the potential difference. However, the internal structure of the battery prevents this from happening.
When the negative and positive terminals of a battery connect with a conducting cable, electrons in the negative end suddenly find a path of least resistance to flow towards the positive. The electrons flow to the positive side of the metal by entering the “sea of electrons”.
Imagine the electrons feeling..
If there is a difference between the negative and positive ends of the battery’s electrons, then there will be a current or flow of electrons in conductor. If the difference is zero, then the battery is dead. It cannot produce a current.
Now you know that electrons are released by power sources. They just flow from the point at which they are most excited to the lowest potential. This is their natural instinct. They do not get destroyed or altered by the electric current flowing through a circuit.