1. Energy is not continuous, but comes in small but discrete units. 2. The elementary particles behave both like particles and like waves. 3. The movement of these particles is inherently random. 4. It is physically impossible to know both the position and the momentum of a particle at the same time. The more precisely one is known, the less precise the measurement of the other is. 5. The atomic world is nothing like the world we live in.
There is a new branch of science called Super String Theory or M Theory, which is further demonstrating that the material universe is just an illusion. Every atom and particle is not solid but made up of what theorectical physicists call strings of vibrational energy and they are so small that if an atom is the size of the Solar system, each one of the strings that make it up would be anywhere from the size of a tree on Earth or the size of an atom compared to the size of the atom, which has been extrapolated to the size of the Solar System. If there is no solidity whatsoever then it is easy to understand how the entire universe can expand from the point of the Big Bang.
In former times scientists thought that light consists of waves and that electrons, neutrons and protons are particles. But Scientists have discovered that sometimes light has got a wave character and sometimes light has got a particle character but not only light also the other particles which I mentioned sometimes have got a wave character. There is an experiment which shows that light can have a particle character. For this experiment we need a metal plate. When we irradiate this metal plate with light it can happen that some of the electrons of some atoms will leave their atomic shell. But when no electron leaves the atomic shell a classical physicist would say that the intensity is to low and what we need a stronger light source or that we must give the light nearer to the metal plate. But this would not help, because light consists of photons and when we have got a higher intensity there are more photons which bombard the electrons, but one electron can only absorb one photon. This means that the energy of the photon is responsible, wheather an electron leaves his atomic shell or not. The electrons are holded by the positive charged atomic nucleus and so they need a certain energy to break out. So we need radiation with a shorter wavelength to give the electrons enough energy. If the wavelength is shorter the energy and the frequency are higher. Which wavelength do we need depends on the atoms. Simple light is to little so that we need ultraviolet light for example. All this is called photoelectric effect. The best possibility to make this experiment is with an electroscope. There is also an experiment which show us that electrons can have a wave character. It is the double gap experiment which I will describe later, because it is the most important experiment for quantum physics and the consequences of it might change your conception of the world.