Questions: Complete the table with the number of inner, outer, and valence electrons present in an atom of each element. Number of electrons Element Inner Outer Valence -------------------------------- Br Cs Cr Sr

Solution Steps

To determine the number of inner, outer, and valence electrons for each element, we need to understand their electron configurations. The electron configuration provides the distribution of electrons in an atom's orbitals.

• Bromine (Br): Atomic number 35. Electron configuration: \([ \text{Ar} ] \, 3d^{10} \, 4s^2 \, 4p^5\).
• Cesium (Cs): Atomic number 55. Electron configuration: \([ \text{Xe} ] \, 6s^1\).
• Chromium (Cr): Atomic number 24. Electron configuration: \([ \text{Ar} ] \, 3d^5 \, 4s^1\).
• Strontium (Sr): Atomic number 38. Electron configuration: \([ \text{Kr} ] \, 5s^2\).

• Inner Electrons: Electrons not in the outermost shell.
• Outer Electrons: Electrons in the outermost shell.
• Valence Electrons: Electrons available for bonding, typically in the outermost shell.

• Inner: 28 (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰)
• Outer: 7 (4s² 4p⁵)
• Valence: 7 (4s² 4p⁵)

• Inner: 54 (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶)
• Outer: 1 (6s¹)
• Valence: 1 (6s¹)

• Inner: 18 (1s² 2s² 2p⁶ 3s² 3p⁶)
• Outer: 6 (3d⁵ 4s¹)
• Valence: 6 (3d⁵ 4s¹)

• Inner: 36 (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶)
• Outer: 2 (5s²)
• Valence: 2 (5s²)

Final Answer