Do electrons show interference?

Yes, electrons can be brought to interfere with themselves. This can actually be shown in a double slit experiment, just as with photons. The electron you are thinking of is a localized particle in space.

Can you tell where an electron is?

You don’t know exactly where the electron is, but you know where it is most likely and least likely to be found. In an atom, the wave function can be used to model a shape, called an orbital, which contains the area an electron is almost certain to be found inside.

Do matter exist when not observed?

It is absolutely not true that states of matter do not exist when they are not noticed. The correct statement is that a quantum system usually exists in a state that is not at all like the states of the classical world. Simply put, it cannot be described by ordinary numbers.

Is it possible to observe an electron?

If indeed Quantum Mechanics describes how the world “really works,” then the concept of observing an electron may actually be impossible due to the statistical behaviors of quantum waveform collapse. Nothing is observed without some physical process ‘performing’ the observation.

Can you tell the position of an electron without its velocity?

The position of an electron can be observed, but not with knowing its velocity. The often shown example of this in engineering and physics classes in the image of an arrow in the forest. You can clearly see where it is, but from an image of the arrow, you cannot tell how fast it is going.

Why can’t we see electrons directly in Sparks?

We also “see” electrons directly in sparks, our eyes and brain are not equipped to see the light as clearly as the light reflected from the cloud, but this is a limitation of our biology, our instruments can. So I think that the statement is vacuous.

Can the position of an electron be observed instantaneously?

While it can be observed instantaneously, it cannot be determined both where it is and its velocity. The speed of an electron can be observed, but not with knowing its position. The position of an electron can be observed, but not with knowing its velocity.