What happens to the atomic radius when an atom loses an electron to become a cation?
The atomic radius decreases
When an atom loses an electron to form a cation, the number of protons in the nucleus stays the same but the number of electrons decreases.
The same nuclear charge now pulls on fewer electrons, so the effective nuclear charge per electron increases and the remaining electrons are drawn closer to the nucleus.
Often the outermost shell is lost completely (e.g. Na → Na⁺ loses its 3s shell), which shrinks the size further.
So a cation is always smaller than its parent atom. The radius does not increase (that happens when an anion forms), cannot become zero, and does not remain the same.
Hence, the answer is The atomic radius decreases.
Similar Questions
The atomic number of an element ‘X’ is 12, the element will show a valency of _______:
Important Questions from Classification of Elements and Periodicity in Properties
- Which one of the following statements about alkaline earth metals is NOT true ?
- What element is a greenish yellow gas with a characteristic smell at room temperature?
- In the periodic table, as one goes down the group, which property doesn't change?
- Which of the following is a copper ore?
- Which scientist invented the Periodic table?
