Isobars of elements have same: 

The correct answer is Mass numbers.

Key Points

• Isobars are atoms of different elements that have the same mass numbers but different atomic numbers.
• Mass number is the total number of protons and neutrons in an atom's nucleus.
• Because they are different elements, isobars have different chemical properties but share the same mass.
• An example of isobars includes Carbon-14 (₆C¹⁴) and Nitrogen-14 (₇N¹⁴), both of which have a mass number of 14 but differ in the number of protons and neutrons.
• The term "isobar" comes from the Greek words "iso" (equal) and "baros" (weight).

Additional Information

• Atomic Number:
  • It is the number of protons in an atom's nucleus and determines the element's identity.
  • Isobars have different atomic numbers, meaning they belong to different elements.
• Neutrons:
  • Isobars differ in the number of neutrons, which balances the difference in the number of protons to maintain the same mass number.
• Isotopes:
  • In contrast to isobars, isotopes are atoms of the same element with the same atomic number but different mass numbers due to a varying number of neutrons.
  • Example: Carbon-12, Carbon-13, and Carbon-14 are isotopes of Carbon.
• Applications of Isobars:
  • Isobars like Carbon-14 are used in radiocarbon dating to estimate the age of archaeological artifacts.
  • Isobars also find applications in nuclear medicine and research.