That basically refers to particles that are not made up of smaller particles. For example, protons and neutrons are made up of smaller particles (quarks), so they are NOT point-like. On the other hand, the quarks themselves, electrons, and photons are believed to be truly elementary - not made up of smaller particles.
Was, for example, "I was at the party."
Ion of hydrogen.
Yes, it is true.
Example: proton, positron.
A non-example of a particle would be a continuous, unbroken physical substance, such as a fluid or gas. These substances do not consist of individual, distinct particles like atoms or molecules.
An example of the expectation value in quantum mechanics is the average position of a particle in a one-dimensional box. This value represents the most likely position of the particle when measured.
A pure substance has only one kind of particle. Sulfur is an example of a pure substance.
Particle in the English language refers to the very tiny pieces like the chalk dust.
A dust particle.
Particles can vary in size depending on the type of particle. For example, an atom is about one angstrom in size, while a typical virus particle can range from 20 to 400 nanometers. In contrast, a dust particle might be around 10 micrometers in size.
For example protons and neutrons are formed from quarks and gluons.
Light is currently considered to be the fastest known particle(s) in existence. There are theoretical particles that can function well past the speed of light. One example of such theoretical particle is the Tachyon.