Include types of atoms, for example isotopes, and how they are different from a typical atom.

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Atoms are composed of particles: electrons, protons, and neutrons. Based on their stability, atoms can be any one of four types:

1.) Stable atom: These are the typical atoms. Their constituent numbers of electrons, protons, and neutrons stay the same. For example, a stable sodium atom will always contain 11 protons, 11 electrons, and 12 neutrons.

2.) Isotopes: These are the atoms that have the same number of protons but a different number of neutrons. As a result, they have the same atomic number but different atomic masses. For example, uranium-235 and uranium-238 are isotopes of uranium. Both of these have 92 protons, but U-235 has 143 neutrons, while U-238 has 146 neutrons.

3) Radioactive atoms: These atoms are unstable and achieve stability by emitting excess particles. Uranium is a radioactive atom.

4) Ion: When an atom gains or loses an electron or electrons, it becomes an ion. For example, the chlorine atom accepts 1 electron to become the chloride ion.

Hope this helps.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial