Discussion Overview
The discussion revolves around the varying atomic radii values for iron (Fe) and nickel (Ni) encountered in different sources, particularly in the context of a homework problem involving plane density calculations for these metals. Participants explore the implications of these discrepancies and the definitions of atomic radius.
Discussion Character
- Homework-related
- Debate/contested
- Conceptual clarification
Main Points Raised
- One participant notes differing atomic radii values for Fe from various sources, including Wikipedia and Chemicool, and questions which value to trust.
- Another participant asks whether the atomic radii in question refer to zero valent iron and nickel or their ionic forms, highlighting that ionic radii depend on coordination number and oxidation state.
- A suggestion is made to check the IUPAC site for atomic radius data, although the reliability of the source is questioned.
- It is proposed that the atomic radius values might pertain to the gas phase, and that the atomic radius can change when a metal atom is part of a lattice structure.
- One participant expresses confusion about the definition of atomic radius, suggesting that different interpretations could lead to the observed discrepancies in values.
- A participant shares their calculations for plane density using specific atomic radii for Fe and Ni, but expresses uncertainty about the correctness of the values used.
- Another participant recommends consulting a specific textbook for potentially reliable information on atomic radii.
Areas of Agreement / Disagreement
Participants do not reach a consensus on which atomic radius values to trust, and multiple competing views regarding the definition and context of atomic radius remain unresolved.
Contextual Notes
There are limitations regarding the definitions of atomic radius, the context in which these values are measured (gas phase vs. solid state), and the potential influence of coordination number and oxidation state on ionic radii.
