Question

State Bohr-Bury rules for distribution of electrons in different shells and apply them for writing electronic configuration for Z=10, 20 and 30.

Answer 1

• Bohr-Bury rule states
• the arrangement of electrons around the nucleus in different energy levels or energy shells.
• The electrons first occupy the shell with the lowest energy,I.e, closer to the nucleus.
• The first or innermost shell (K or n=1) can take 2 electrons.
• The second (L or n=2) can contain up to 8 electrons.
• From the third shell (M,n=3) shells become bigger. The third shell can accommodate up to 18 electrons.
• General formula of the maximum number of electrons in any shell=2n²
• Electronic configuration for
• Z=10, neon=2, 8.
• Z=20, calcium=2, 8, 8, 2.
• Z=30,zinc=2, 8, 18, 2.