Question

Write the expected electron configurations for each of the following atoms: \(\mathrm{Cl}, \mathrm{Sb}, \mathrm{Sr}, \mathrm{W}, \mathrm{Pb}, \mathrm{Cf}\).

Short answer

The electron configurations for the given atoms are as follows: \(\mathrm{Cl}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^5}\) \(\mathrm{Sb}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^3}\) \(\mathrm{Sr}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2}\) \(\mathrm{W}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^4}\) \(\mathrm{Pb}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^{10}, 6p^2}\) \(\mathrm{Cf}\): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^{10}, 6p^6, 7s^2, 5f^{10}}\)

Step-by-step solution

Determine the atomic number of each element

For each element, find its atomic number from the periodic table. The atomic number indicates the number of protons and also the number of electrons in a neutral atom. \(\mathrm{Cl}\) - Chlorine has an atomic number of 17. \(\mathrm{Sb}\) - Antimony has an atomic number of 51. \(\mathrm{Sr}\) - Strontium has an atomic number of 38. \(\mathrm{W}\) - Tungsten has an atomic number of 74. \(\mathrm{Pb}\) - Lead has an atomic number of 82. \(\mathrm{Cf}\) - Californium has an atomic number of 98.

List the orbital filling order

Remember the orbital filling order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p. Use this order to fill each atom's electrons into orbitals until the atom's total number of electrons is reached.

Determine the electron configuration of each element

Using the atomic number and the orbital filling order, write the electron configuration for each element. \(\mathrm{Cl}\) (17 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^5}\) \(\mathrm{Sb}\) (51 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^3}\) \(\mathrm{Sr}\) (38 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2}\) \(\mathrm{W}\) (74 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^4}\) \(\mathrm{Pb}\) (82 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^{10}, 6p^2}\) \(\mathrm{Cf}\) (98 electrons): \(\mathrm{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^{10}, 4p^6, 5s^2, 4d^{10}, 5p^6, 6s^2, 4f^{14}, 5d^{10}, 6p^6, 7s^2, 5f^{10}}\) Note that these configurations assume a simple filling order based on the Aufbau principle. In some cases, electronic configurations can slightly differ from the order shown, but these are good approximate representations of the electronic structure for these elements.