. The valence shell of calcium contains
A: 2 electrons
B: 4 electrons
C: 6 electrons
D: 8 electrons
- Calcium has atomic number 20.
- Its electronic configuration is 2, 8, 8, 2
- The valence shell means the outermost shell of an element which has valence electrons.
- Hence its valence shell contains 2 electrons.
Hence the correct answer is (A) 2 electrons.