Are the planets held in orbit in exactly the same way as electrons orbit the nucleus?
When a planet moves around the sun, you can plot a definite path for it that is called an orbit. A simple view of the atom looks similar and you may have pictured electrons as orbiting around the nucleus. The truth is different, and electrons inhabit regions of space known as orbitals. Orbits and orbitals sound similar, but they have quite different meanings. A planet orbits because of gravity. An electron moves because of the electromagnetic force, which is trillions of times stronger than the gravitational force. To plot a path for something you need to know exactly where the object is and be able to work out exactly where it’s going to be an instant later. You can’t do this for electrons. The Heisenberg Uncertainty Principle says – loosely – that you can’t know with certainty both where an electron is and where it’s going next. (What it actually says is that it is impossible to define with absolute precision, at the same time, both the position and the momentum of an electron.) That
