Is It really true???

Quantum Theory, in physics, description of the particles that make up matter and how they interact with each other and with energy. Quantum theory explains in principle how to calculate what will happen in any experiment involving physical or biological systems, and how to understand how our world works. The name “quantum theory” comes from the fact that the theory describes the matter and energy in the universe in terms of single indivisible units called quanta (singular quantum). Quantum theory is different from classical physics. Classical physics is an approximation of the set of rules and equations in quantum theory. Classical physics accurately describes the behavior of matter and energy in the everyday universe. For example, classical physics explains the motion of a car accelerating or of a ball flying through the air. Quantum theory, on the other hand, can accurately describe the behavior of the universe on a much smaller scale, that of atoms and smaller particles. The rules of classical physics do not explain the behavior of matter and energy on this small scale. Quantum theory is more general than classical physics, and in principle, it could be used to predict the behavior of any physical, chemical, or biological system. However, explaining the behavior of the everyday world with quantum theory is too complicated to be practical.

Quantum theory not only specifies new rules for describing the universe but also introduces new ways of thinking about matter and energy. The tiny particles that quantum theory describes do not have defined locations, speeds, and paths like objects described by classical physics. Instead, quantum theory describes positions and other properties of particles in terms of the chances that the property will have a certain value. For example, it allows scientists to calculate how likely it is that a particle will be in a certain position at a certain time.

Quantum description of particles allows scientists to understand how particles combine to form atoms. Quantum description of atoms helps scientists understand the chemical and physical properties of molecules, atoms, and subatomic particles. Quantum theory enabled scientists to understand the conditions of the early universe, how the Sun shines, and how atoms and molecules determine the characteristics of the material that they make up. Without quantum theory, scientists could not have developed nuclear energy or the electric circuits that provide the basis for computers.

Quantum theory describes all of the fundamental forces—except gravitation—that physicists have found in nature. The forces that quantum theory describes are the electrical, the magnetic, the weak, and the strong. Physicists often refer to these forces as interactions, because the forces control the way particles interact with each other. Interactions also affect spontaneous changes in isolated particles.

Why does salt dissolve in water and not gasoline?

This is a case of like dissolves like.

Water and salt both consist of what we call polar molecules. This means electrons in the molecule are not equally shared between the atoms of the molecule, causing a partial charge on the molecule's atoms.

Water, for instance, contains two hydrogen atoms and one oxygen atom. The electrons in the water molecule spend more time around the oxygen atom than around the hydrogen atoms.

Since electrons are negatively charged, the oxygen part of the molecule is partially negatively charged and the hydrogen parts of the atom are partially positively charged.

In salt, which is made of sodium and chlorine, the shared electrons spend almost all of their time on the chlorine side, making the chlorine negatively charged, and very little time on the sodium side, making the sodium positively charged.

When salt is put into water, the positively charged side of water molecules surround the negatively charged chlorine, and the negatively charged side of the water molecules surrounds the positively charged sodium. This breaks the sodium chloride bond and the salt is dissolved.

Gasoline contains non-polar molecules, which means the atoms in those molecules share electrons equally.

This also means there is no partial charge on those molecules to be attracted to the charges on the sodium or chlorine molecules of salt. Therefore, salt doesn't dissolve in gasoline.