d and f BLOCK ELEMENTS

What is the ground state electronic configuration of Platinum (Pt, Z=78)?

• [Xe] 4f¹⁴ 5d⁸ 6s²
• [Xe] 4f¹⁴ 5d¹⁰
• [Xe] 4f¹⁴ 5d¹⁰ 6s¹
• [Xe] 4f¹⁴ 5d⁹ 6s¹

What is the ground state electronic configuration of Iridium (Ir, Z=77)?

• [Xe] 4f¹⁴ 5d⁹
• [Xe] 4f¹⁴ 5d⁶ 6s³
• [Xe] 4f¹⁴ 5d⁸ 6s¹
• [Xe] 4f¹⁴ 5d⁷ 6s²

What is the ground state electronic configuration of Osmium (Os, Z=76)?

• [Xe] 4f¹⁴ 5d⁸
• [Xe] 4f¹⁴ 5d⁵ 6s³
• [Xe] 4f¹⁴ 5d⁷ 6s¹
• [Xe] 4f¹⁴ 5d⁶ 6s²

What is the ground state electronic configuration of Rhenium (Re, Z=75)?

• [Xe] 4f¹⁴ 5d⁷
• [Xe] 4f¹⁴ 5d⁴ 6s³
• [Xe] 4f¹⁴ 5d⁶ 6s¹
• [Xe] 4f¹⁴ 5d⁵ 6s²

Why are the densities of transition elements generally high?

• They contain mostly light elements
• Low atomic masses and large atomic radii
• Ionic bonding creates large intermolecular spaces
• High atomic masses combined with relatively small atomic radii lead to closely packed atoms.