Write the electron arrangement for the following element:Calcium (Z = 20)

• A. 2-2-6-2-6-2
• B. 2-8-8-2
• C. 2-16-2
• D. 2-8-8-1
• E. 1-2-2-8-2

Answer: (B)

Verified step by step guidance

1. Identify the atomic number of calcium, which is 20. This means calcium has 20 electrons to arrange.
2. Understand that electrons fill orbitals in a specific order based on increasing energy levels, following the Aufbau principle.
3. Begin filling the electron orbitals: Start with the 1s orbital, which can hold 2 electrons, so the first two electrons go into 1s.
4. Next, fill the 2s orbital with 2 electrons, followed by the 2p orbital, which can hold 6 electrons. This accounts for 10 electrons so far.
5. Continue by filling the 3s orbital with 2 electrons, then the 3p orbital with 6 electrons, and finally, place the remaining 2 electrons in the 4s orbital, resulting in the electron configuration: 2-8-8-2.