d Block - General Properties and Trends - UNSOLVED PRACTICE SET
Chapter: d and f Block Elements | Topic: d Block General Properties and Trends
D BLOCK - GENERAL PROPERTIES AND TRENDS - UNSOLVED PRACTICE SET
Topic: d Block General Properties and Trends
Multiple Choice Questions
Q1. The general electronic configuration of d-block elements is:
- (n-1)d¹⁻¹⁰ ns¹⁻²
- (n-1)d¹⁰ ns⁰⁻²
- (n-1)d⁰ ns²
- (n-1)d¹⁰ ns² np⁶
Q2. Which of the following is NOT a transition element?
- Zn
- Fe
- Cu
- Cr
Q3. The element with the highest melting point in the 3d series is:
- Sc
- Ti
- Cr
- Zn
Q4. Transition elements show high enthalpy of atomization because of:
- Weak metallic bonds
- Strong metallic bonds due to unpaired d-electrons
- Large atomic size
- Low ionization energy
Q5. Which transition metal has the highest density?
- Fe
- Cu
- Os
- Ag
Q6. The atomic radii of transition elements:
- Increase regularly across a period
- Decrease regularly across a period
- First decrease, then remain almost constant, and finally increase slightly
- Show no regular trend
Short Answer Questions
Q7. Why are d-block elements called transition elements? Explain the origin of this name.
Q8. Transition elements have high melting and boiling points. Explain this property in terms of their electronic configuration.
Q9. Why do transition metals exhibit higher enthalpies of atomization compared to s-block elements?
Q10. The atomic and ionic radii of transition elements are smaller than those of s-block elements in the same period. Explain why.
Q11. Your stainless steel tiffin box doesn't rust like ordinary iron. Which transition element is responsible for this property? Explain briefly.
Q12. Why do transition elements show variable oxidation states? What is the maximum oxidation state shown by Mn?
Long Answer Questions
Q13. Describe the general characteristics of transition elements (d-block elements). Discuss at least six properties with explanations based on their electronic configuration.
Q14. (a) Explain the trends in atomic radii, ionic radii, and density across the first transition series (3d series).
(b) Why does the atomic radius of Cu (128 pm) deviate from the expected trend in the 3d series?
(c) Compare the melting points of transition metals with those of s-block and p-block metals. Give reasons for the differences.
Q15. (a) Why do transition metals exhibit high thermal and electrical conductivity?
(b) Explain why transition metals are hard, have high density, and are malleable and ductile.
(c) A student notices that copper wires are used for electrical wiring while iron is used for construction. Based on the properties of transition metals, explain why these specific metals are chosen for these applications.
Numerical / Application-Based Problems
Q16. The following data gives the melting points of first row transition elements:
| Element | MP (°C) |
|---|---|
| Sc | 1541 |
| Ti | 1668 |
| V | 1917 |
| Cr | 1907 |
| Mn | 1246 |
| Fe | 1538 |
| Co | 1495 |
| Ni | 1455 |
| Cu | 1085 |
(a) Plot a rough graph of melting point vs. atomic number.
(b) Identify the element with the highest and lowest melting points.
(c) Explain why Mn and Zn have relatively low melting points compared to their neighbours.
(d) Why does the melting point increase from Sc to Cr and then decrease towards Zn?
(e) A blacksmith needs to melt a mixture containing equal amounts of Fe and Cu. At what minimum temperature should the furnace be set?
Q17. The atomic radii (in pm) of 3d series elements are given below:
| Element | Radius (pm) |
|---|---|
| Sc | 162 |
| Ti | 147 |
| V | 134 |
| Cr | 128 |
| Mn | 127 |
| Fe | 126 |
| Co | 125 |
| Ni | 124 |
| Cu | 128 |
(b) Why does the radius decrease from Sc to Ni and then increase from Ni to Zn?
(c) Calculate the percentage decrease in radius from Sc to Ni.
(d) The ionic radius of Fe²⁺ is 77 pm while that of Fe³⁺ is 65 pm. Explain why Fe³⁺ is smaller than Fe²⁺.
(e) Compare the atomic radius of Cu (128 pm) with that of Zn (134 pm). Why does Zn have a larger radius despite having more protons?
Q18. In a school science exhibition, students display models of transition metals and their uses in everyday Indian life.
(a) One student displays a copper water bottle (tamra jal) used in Ayurvedic practice. Explain why copper is used for storing water, mentioning two properties of copper relevant to this use.
(b) Another student shows stainless steel utensils used in every Indian kitchen. Stainless steel contains iron, chromium, and nickel. Why is chromium added to iron to make stainless steel?
(c) A third student demonstrates how a coin (containing Cu and Ni) can be attracted to a magnet after being heated and cooled in a magnetic field. What property of transition metals does this demonstrate?
(d) The students compare the density of transition metals with aluminium (a p-block metal). Why are transition metals generally denser than p-block metals in the same period?
(e) The teacher asks: "If you had to choose a metal for making aircraft parts, would you choose a transition metal or an s-block metal? Why?" Give your answer with reasoning.