Home › CBSE Class 9 › chemistry › atomicstructure › An atom of Magnesium loses 2 electrons. The resu…
An atom of Magnesium loses 2 electrons. The resulting Mg²⁺ ion has the same electron configuration as which noble gas?
AHelium (He)
BNeon (Ne)
CKrypton (Kr)
DArgon (Ar)
Answer & Solution
Correct answer: B. Neon (Ne)
Magnesium (Z=12) configuration: 2, 8, 2. Losing both M-shell electrons gives Mg²⁺ with configuration 2, 8 — exactly the configuration of neon (Z=10). Many ions achieve noble-gas configurations by gaining/losing electrons; this is why neon's configuration shows up in Na⁺, Mg²⁺, Al³⁺, F⁻, O²⁻, etc.
Related questions
Calcium-40 (Z=20, A=40) and Argon-40 (Z=18, A=40) are best described as:Atoms of the SAME element with DIFFERENT mass numbers are called:An atom of chlorine has atomic number Z = 17 and mass number A = 37. The number of neutronThe atomic number (Z) of an element is equal to the:The neutron was discovered by:Bohr's model of the atom fixed Rutherford's instability problem by proposing that electronRutherford's gold foil experiment concluded that most of the atom is:The Rydberg constant for hydrogen, in SI units, is