Where are true protons, neutrons, and electrons?
Where aren't they?
True protons, neutrons, and electrons are all around us. They are in the air we breathe, the chair we sit on, they are nevessarily even in us. You have described the fundamental particles of matter.
Subatomic particles that make up physical matter.
Protons are positively-charged particles that make up a significant mass of an atom. The number of protons in an atom is what makes it unique from any other element - it is responsible for an atom's atomic number. For example, you can't have a carbon atom that has 7 protons, it can only have 6. If it had 7, it would no longer be carbon, it would be nitrogen. Protons are typically written, in shorthand, as
On the other hand, the number of neutrons and electrons can be the same among several atoms and ions. Neutrons are also a relatively massive particle, meaning they're partially responsible for accounting for the atomic mass of a given element. Neutrons are neutrally charged, as hinted by their name. It's typical to see the neutron notation written as
The protons and neutrons are what makes up an atom's nucleus, and they collectively make up each element's mass number. Carbon, for example, has a mass number of of 12 (this is the carbon-12 isomer). Can you calculate how many neutrons it has?
If you calculated 6 neutrons, you're right! How about carbon-14? That's right! 8 neutrons.
Electrons, though not without mass, are so small that they're generally not considered to be part of the element's mass. They are negatively charged, and are often written as
There are times when an atom doesn't have an equal number of protons and electrons. When this occurs, the atom isn't referred to as an element, but rather an ion. An ion is the result of any element carrying either a positive or negative charge. This is generally accomplished by adding or removing electrons, and not protons (although an understanding of nuclear chemistry can help show that sometimes protons can be pulled away, essentially changing the element all together. This is the subject of alchemy).
Feel free to comment if you have any questions!