WebElements Periodic Table » Arsenic » the essentials
Group name: Pnictogen. Period in periodic table: 4. Block in periodic table: p. Shell structure: 2.8.18.5. CAS Registry: . Arsenic atoms have 33 electrons and the shell structure is 2.8.18.5. The ground state electronic configuration of neutral arsenic is [ Ar ]. 3d10. 4s2. 4p3 and the term symbol of arsenic is 4S3/2.