Final answer:
An atom is the smallest particle of an element that retains the chemical properties of that element, determining its identity and behavior in chemical reactions.
Step-by-step explanation:
The smallest particle of an element that has the chemical properties of that element is known as an atom. Atoms are the fundamental building blocks of all matter and are composed of subatomic particles such as electrons, protons, and neutrons.
The number of protons in the nucleus of an atom determines which element it is. Because atoms are incredibly small, with sizes around 100 picometers, they can be observed only with powerful microscopes.
An example to understand the concept of atoms is hydrogen, where one hydrogen atom maintains all properties of the element hydrogen, like bonding with oxygen to form water.
An atom is a particle that consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically-bound swarm of electrons.
The atom is the basic particle of the chemical elements, and the chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. The only atom that has no neutron is protium 1H.
Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element.