How does scientist prove that there's electron, neutron, and proton in an atom?

Answer 1

electrons protons and neutrons are theories which help us understand the phenomena of nature.since the predictions from these theories are experimentally true we go ahead and say they are real.

Answer 2

The concepts of atoms and of the groups of linked atoms called molecules are the foundation of all chemistry (see Atom). An atom is the smallest unit of an element that has the properties of the element; a molecule is the smallest unit of a compound or the form of an element in which atoms bind together that has the properties of the compound or element.
The idea of atoms is an old one. Greek philosopher Leucippus and his student Democritus appear to have originated the idea during the 4th and 5th centuries bc.
All atoms were made of the same basic material, but neither philosopher stated what this material was. The atomic theory was developed further by another Greek philosopher, Epicurus, who added the property of weight to the atoms and attributed a horizontal, as well as a vertical, motion to them in order to explain how atoms combine to form matter. These ideas were restated by Roman poet Lucretius in the 1st century bc.

Atoms are made up of 3 types of particles electrons , protons and neutrons . These particles have different properties. Electrons are tiny, very light particles that have a negative electrical charge (-). Protons are much larger and heavier than electrons and have the opposite charge, protons have a positive charge. Neutrons are large and heavy like protons, however neutrons have no electrical charge. Each atom is made up of a combination of these particle

A neutron walked into a bar and
asked how much for a drink.
The bartender replied,
"for you, no charge."
-Jaime - Internet Chemistry Jokes

The atom above, made up of one proton and one electron, is called hydrogen (the abbreviation for hydrogen is H). The proton and electron stay together because just like two magnets, the opposite electrical charges attract each other. What keeps the two from crashing into each other? The particles in an atom are not still. The electron is constantly spinning around the center of the atom (called the nucleus). The centrigugal force of the spinning electron keeps the two particles from coming into contact with each other much as the earth's rotation keeps it from plunging into the sun. Taking this into consideration, an atom of hydrogen


In an electrically neutral atom, the positively charged protons are always balanced by an equal number of negatively charged electrons. As we have seen, hydrogen is the simplest atom with only one proton and one electron. Helium is the 2nd simplest atom. It has two protons in its nucleus and two electrons spinning around the nucleus. With helium though, we have to introduce another particle. Because the 2 protons in the nucleus have the same charge on them, they would tend to repel each other, and the nucleus would fall apart. To keep the nucleus from pushing apart, helium has two neutrons in its nucleus. Neutrons have no electrical charge on them and act as a sort of nuclear glue, holding the protons, and thus the nucleus, together