Question
Explain the anomalous behavior of copper and chromium.
✓
Answer
i. Copper:
- Copper (Cu) has atomic number 29.
- Its expected electronic configuration is $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^2 3 d^9$.
- The 3d orbital is neither half-filled nor fully filled. Hence, it has less stability.
- Due to interelectronic repulsion forces, one 4 s electron enters into 3 d orbital. This makes 3 d orbital completely filled and 4 s orbital half-filled which gives extra stability and the electronic configuration of Cu becomes, $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^1 3 d^{10}$.
- Chromium (Cr) has atomic number 24.
- Its expected electronic configuration is $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^2 3 d^4$.
- The 3d orbital is less stable as it is not half-filled.
- Due to inter electronic repulsion forces, one 4 s electron enters into 3 d orbital. This makes 4 s and 3 d orbitals half-filled which gives extra stability and the electronic configuration of Cr becomes, $1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^1$ $3 d^5$.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Electrophile and nucleophile
Consider a sample of a gas in a cylinder with a movable piston.
Show digramatically the changes in the position of piston, if
a. Pressure is increased from 1.0 bar to 2.0 bar at constant temperature.
b. Temperature is decreased from 300 K to 150 K at constant pressure
c. Temperature is decreased from 400 K to 300 K and pressure is decreased from 4 bar to 3 bar.
How can a period, group and block of the element be determined?
In repeated measurements in volumetric analysis, the end-points were observed as 11.15 mL, 11.17 mL, 11.11 mL and 11.17 mL. Calculate mean absolute deviation and relative deviation.
Calculate the binding energy per nucleon for the formation of ${ }_2^4 He$ nucleus. Mass of ${ }_2^4 He$ atom $=4.0026 u$.
→Explain the trend in electronegativity
i. across a period
ii. down a group
i. across a period
ii. down a group
Write postulates of Bohr’s Theory of hydrogen atom.
Identify the type of orbital overlap present in
a. $H _2$
b. $F_2$
c. H-F molecule.
Explain diagramatically.
→a. $H _2$
b. $F_2$
c. H-F molecule.
Explain diagramatically.
Explain the effect of dipole moment on boiling point with an example.