What defines two elements as isobars?
Same mass number but different atomic numbers
Isobars are atoms of different elements that have the same mass number (total protons + neutrons) but different atomic numbers (different number of protons). For example, argon-40 (Z = 18) and calcium-40 (Z = 20) both have mass number 40, yet they are distinct elements.
"Same number of electrons" describes a neutral atom only in terms of its protons; equal electron count would mean the same atomic number, which would make them the same element, not isobars.
"Same number of neutrons" defines isotones, not isobars.
"Same atomic number" defines isotopes (same element, different mass numbers), which is the opposite condition.
Hence, two elements are isobars when they have the same mass number but different atomic numbers.
Similar Questions
According to Bohr’s model, electrons revolve around the nucleus in:
Two isotopes of chlorine are present in nature: chlorine-35 and chlorine-37. Which statement best explains their chemical behavior?
Atoms of different elements with different ___________ numbers but the same ______ number are known as isobars.
In Rutherford’s α-particle scattering experiment, the conclusion that most of the atom is empty space was drawn because:
Which statement about mass number is correct?
Which of the following best represents the characteristic properties of isotopes?
Which of the following correctly describes a proton?
Which of the following correctly defines the mass number of an atom?
Imagine a scientist is analyzing an unknown atom and finds it has a mass number of 24 and an atomic number of 12. If the atom gains two neutrons due to a nuclear reaction, what will be its new mass number?
Which of the following statements is/are CORRECT?
Statement I: The maximum number of electrons in any shell is given by 2n2.
Statement II: The third shell (n=3) can hold up to 12 electrons.
Important Questions from Structure of Atom
- How many moles of He atoms are present in its 20 u mass ?
Which of the following electron transition in hydrogen atom will require largest amount of energy?
A species having 8 electrons in the third shell is very reactive while the other species having 8 electrons in the third shell is very inactive they are :
Which of the following is the general formula for saturated hydrocarbons?
Which one of the following is the average atomic mass of chlorine atom?
