Isobars are atoms or ions that have the same number of nucleons (total number of protons and neutrons) but different atomic numbers (number of protons). In other words, isobars have different chemical properties but similar physical properties.

Examples of Isobars:
1. Carbon-14 and Nitrogen-14
2. Potassium-40 and Calcium-40
3. Chlorine-37 and Argon-37
4. Uranium-235 and Thorium-231
5. Cobalt-60 and Nickel-60

Explanation:
1. Carbon-14 and Nitrogen-14: Carbon-14 is used in radiocarbon dating while Nitrogen-14 is a stable isotope of nitrogen. Both have 14 nucleons but Carbon-14 contains 6 protons while Nitrogen-14 contains 7 protons.
2. Potassium-40 and Calcium-40: Potassium-40 is a radioactive isotope of potassium that decays to form Calcium-40. Both have 20 neutrons and 40 nucleons but Potassium-40 contains 19 protons while Calcium-40 contains 20 protons.
3. Chlorine-37 and Argon-37: Chlorine-37 is a radioactive isotope of chlorine while Argon-37 is a stable isotope of argon. Both have 18 neutrons and 37 nucleons but Chlorine-37 contains 17 protons while Argon-37 contains 18 protons.
4. Uranium-235 and Thorium-231: Uranium-235 is a fissile isotope of uranium used in nuclear reactors while Thorium-231 is a radioactive isotope of thorium. Both have 92 nucleons but Uranium-235 contains 143 neutrons while Thorium-231 contains 139 neutrons.
5. Cobalt-60 and Nickel-60: Cobalt-60 is a radioactive isotope of cobalt used in radiation therapy while Nickel-60 is a stable isotope of nickel. Both have 60 nucleons but Cobalt-60 contains 27 protons while Nickel-60 contains 28 protons.

Conclusion:
Isobars are atoms or ions that have the same number of nucleons but different atomic numbers. They have different chemical properties but similar physical properties. Examples of isobars include Carbon-14 and Nitrogen-14, Potassium-40 and Calcium-40, Chlorine-37 and Argon-37, Uranium-235 and Thorium-231, and Cobalt-60 and Nickel-60.