1. In the long form periodic table, the \(d\)-block is located between which two blocks?
ⓐ. \(p\)-block and \(f\)-block
ⓑ. \(s\)-block and \(p\)-block
ⓒ. \(s\)-block and \(f\)-block
ⓓ. \(p\)-block and noble gas group
Correct Answer: \(s\)-block and \(p\)-block
Explanation: The \(d\)-block occupies the middle region of the long form periodic table. It appears after the \(s\)-block elements on the left and before the \(p\)-block elements on the right. This is why these elements are often described as lying in the transition region of the table. Their position is a structural feature of the periodic table, not just a naming convention.
2. The first appearance of \(d\)-block elements occurs in which period?
ⓐ. Period 2
ⓑ. Period 3
ⓒ. Period 5
ⓓ. Period 4
Correct Answer: Period 4
Explanation: The \(d\)-subshell first becomes available for filling after the \(4s\) subshell, so the first \(d\)-block series begins in period 4. That series is the \(3d\) series. Periods 2 and 3 contain only \(s\)- and \(p\)-block elements. This makes period 4 the first period in which the \(d\)-block appears.
3. The first transition series corresponds to filling of which subshell?
ⓐ. \(3d\)
ⓑ. \(4d\)
ⓒ. \(5d\)
ⓓ. \(4f\)
Correct Answer: \(3d\)
Explanation: The first transition series runs from scandium to zinc and is associated with filling of the \(3d\) subshell. It belongs to period 4 of the periodic table. The \(4d\) and \(5d\) series occur in lower rows, while \(4f\) belongs to the inner transition elements. So the correct series label for the first transition row is \(3d\).
4. Where are the inner transition elements generally shown in the periodic table?
ⓐ. On the extreme left before the \(s\)-block
ⓑ. Between the halogens and noble gases
ⓒ. In two separate rows at the bottom
ⓓ. Above period 2 as a short extra strip
Correct Answer: In two separate rows at the bottom
Explanation: The inner transition elements are usually displayed in two detached rows below the main body of the periodic table. This arrangement keeps the table compact and readable. These rows correspond to the \(4f\) and \(5f\) series. Their separate display does not mean they are outside the periodic table; it is mainly a layout choice.
5. Which pairing is correct?
ⓐ. Period 4 \(\rightarrow\) \(4d\) series
ⓑ. Period 5 \(\rightarrow\) \(4d\) series
ⓒ. Period 6 \(\rightarrow\) \(5f\) series
ⓓ. Period 7 \(\rightarrow\) \(4f\) series
Correct Answer: Period 5 \(\rightarrow\) \(4d\) series
Explanation: The second transition series belongs to period 5 and is called the \(4d\) series. The first transition series is the \(3d\) series in period 4, and the \(5d\) series belongs to period 6. The \(4f\) and \(5f\) series are the inner transition series, not the main \(d\)-block transition rows. Matching period 5 with \(4d\) is therefore the correct pairing.
6. The series associated with the inner transition elements of period 6 is
ⓐ. \(4f\)
ⓑ. \(5f\)
ⓒ. \(3d\)
ⓓ. \(4d\)
Correct Answer: \(4f\)
Explanation: The inner transition elements of period 6 are the lanthanoids, and they are associated with filling of the \(4f\) orbitals. These elements are shown in the first of the two separated rows at the bottom of the periodic table. The \(5f\) series belongs to the next inner transition row. Therefore, period 6 inner transition elements correspond to the \(4f\) series.
7. Which sequence correctly shows the \(d\)-series from top to bottom in the periodic table?
ⓐ. \(5d, 4d, 3d\)
ⓑ. \(4d, 3d, 5d\)
ⓒ. \(3d, 5d, 4d\)
ⓓ. \(3d, 4d, 5d\)
Correct Answer: \(3d, 4d, 5d\)
Explanation: The topmost transition row is the \(3d\) series in period 4. Below that comes the \(4d\) series in period 5, followed by the \(5d\) series in period 6. This order follows the increasing period number as one moves downward in the table. So the correct top-to-bottom sequence is \(3d, 4d, 5d\).
8. Which set contains only inner transition series labels?
ⓐ. \(3d, 4d\)
ⓑ. \(4d, 5d\)
ⓒ. \(4f, 5f\)
ⓓ. \(3d, 5f\)
Correct Answer: \(4f, 5f\)
Explanation: Inner transition elements are the \(f\)-block elements. Their two series are the \(4f\) series and the \(5f\) series. In contrast, \(3d\), \(4d\), and \(5d\) refer to the transition elements of the \(d\)-block. Therefore, the set containing only inner transition series labels is \(4f, 5f\).
9. Which block is best described as the transition zone in the long form periodic table?
ⓐ. \(d\)-block
ⓑ. \(s\)-block
ⓒ. \(p\)-block
ⓓ. \(f\)-block
Correct Answer: \(d\)-block
Explanation: The \(d\)-block lies between the \(s\)-block and the \(p\)-block in the long form of the table. Because of this middle placement, it acts as a bridge between those two major regions. That is why it is often called the transition zone. This positional idea is different from the stricter definition of a transition element, which depends on electronic configuration.
10. Why are the \(f\)-block elements usually placed separately at the bottom of the periodic table?
ⓐ. They belong only to period 2 and period 3
ⓑ. They are non-metals that do not fit the main table
ⓒ. They always have completely filled \(f\)-orbitals
ⓓ. To avoid making the table too wide
Correct Answer: To avoid making the table too wide
Explanation: If the \(f\)-block elements were inserted directly into the main body, the periodic table would become very broad and difficult to display neatly. To avoid that, the \(4f\) and \(5f\) series are usually shown separately below. This keeps the table compact without changing the actual periodic relationships. So the separate placement is mainly for convenient presentation.
11. Which match is incorrect?
ⓐ. Period 4 \(\rightarrow\) \(3d\) series
ⓑ. Period 5 \(\rightarrow\) \(5d\) series
ⓒ. Period 6 \(\rightarrow\) \(5d\) series
ⓓ. Period 7 \(\rightarrow\) \(5f\) series
Correct Answer: Period 5 \(\rightarrow\) \(5d\) series
Explanation: Period 5 is associated with the \(4d\) series, not the \(5d\) series. The \(5d\) series belongs to period 6. Period 4 correctly matches with \(3d\), and period 7 is associated with the \(5f\) inner transition series. Therefore the incorrect match is the one linking period 5 with \(5d\).
12. Which statement best summarizes the positional relationship of \(d\)- and \(f\)-block elements?
ⓐ. Both are placed entirely on the extreme right of the table
ⓑ. Both occur only in period 3 of the table
ⓒ. The \(d\)-block is central; the \(f\)-block is detached below
ⓓ. The \(d\)-block and \(f\)-block occupy the same central region
Correct Answer: The \(d\)-block is central; the \(f\)-block is detached below
Explanation: The \(d\)-block forms the central region of the long form periodic table. The \(f\)-block, on the other hand, is displayed separately in two rows below the main table. This difference is one of the most important positional distinctions between the two blocks. It also helps explain why the \(f\)-block is called the inner transition series.
13. In the full periodic arrangement, which period contains both a \(5d\) transition series and a \(4f\) inner transition series?
ⓐ. Period 4
ⓑ. Period 5
ⓒ. Period 6
ⓓ. Period 7
Correct Answer: Period 6
Explanation: Period 6 is special because it includes the \(5d\) transition elements in the main body and the \(4f\) lanthanoids in the detached row. The \(4f\) series is usually shown separately only for convenience of table design. Period 4 contains the \(3d\) series, and period 5 contains the \(4d\) series. Period 7 is associated with the \(5f\) inner transition series.
14. Which statement about the detached rows of the periodic table is incorrect?
ⓐ. The first detached row represents the \(5f\) series.
ⓑ. The first detached row represents the \(4f\) series.
ⓒ. The second detached row represents the \(5f\) series.
ⓓ. Both detached rows together represent inner transition elements.
Correct Answer: The first detached row represents the \(5f\) series.
Explanation: The first detached row corresponds to the lanthanoids, which belong to the \(4f\) series. The second detached row corresponds to the actinoids, which belong to the \(5f\) series. Both rows are collectively called inner transition elements. So the only incorrect statement is the one that assigns the first detached row to the \(5f\) series.
15. An element lies in period 5 and is situated between the \(s\)-block and \(p\)-block. It belongs to which series?
ⓐ. \(3d\) series
ⓑ. \(5d\) series
ⓒ. \(4f\) series
ⓓ. \(4d\) series
Correct Answer: \(4d\) series
Explanation: An element in period 5 and placed between the \(s\)- and \(p\)-blocks belongs to the \(d\)-block of that period. The \(d\)-series associated with period 5 is the \(4d\) series. The \(3d\) series belongs to period 4, while the \(5d\) series belongs to period 6. The \(4f\) series is an inner transition series and is not part of the central \(d\)-block row.
16. Which statement correctly distinguishes a transition element from a \(d\)-block element?
ⓐ. Every \(d\)-block element has a partially filled \(d\)-subshell.
ⓑ. It has a partially filled \(d\)-subshell in its atom or common ion.
ⓒ. It is defined only by forming coloured ions in common compounds.
ⓓ. It is an element shown only in the detached rows.
Correct Answer: It has a partially filled \(d\)-subshell in its atom or common ion.
Explanation: The term \(d\)-block element refers to position in the periodic table, whereas the term transition element uses an electronic criterion. A transition element must have an incomplete \(d\)-subshell either in the atom or in one of its common ions. This is why the two sets overlap strongly but are not completely identical. Colour formation is common for many transition elements, but it is not the defining condition.
17. Which of the following is a \(d\)-block element but is not usually regarded as a transition element?
ⓐ. \(Sc\)
ⓑ. \(Ti\)
ⓒ. \(Zn\)
ⓓ. \(Cr\)
Correct Answer: \(Zn\)
Explanation: Zinc belongs to the \(d\)-block because of its position in the periodic table. However, its atom has a completely filled \(d\)-subshell, and its common ion \(Zn^{2+}\) also has a \(d^{10}\) configuration. Because there is no partially filled \(d\)-subshell in either case, zinc is not treated as a typical transition element. The other listed elements satisfy the transition-element definition.
18. Why is \(Zn\) excluded from the list of typical transition elements?
ⓐ. Both \(Zn\) and \(Zn^{2+}\) are \(d^{10}\).
ⓑ. \(Zn\) is placed in the \(p\)-block.
ⓒ. \(Zn\) cannot lose electrons to form a cation.
ⓓ. \(Zn\) has an empty \(d\)-subshell in its common ionic state.
Correct Answer: Both \(Zn\) and \(Zn^{2+}\) are \(d^{10}\).
Explanation: The key point is the electronic configuration, not just table position. Zinc has a filled \(d\)-subshell in the atom, and after losing the \(4s\) electrons it forms \(Zn^{2+}\), which still remains \(d^{10}\). A partially filled \(d\)-subshell is absent in both forms. That is why zinc does not show the usual transition-metal character in the standard sense.
19. Which set contains only transition elements according to the standard definition?
ⓐ. \(Zn, Cd, Hg\)
ⓑ. \(Sc, Zn, Cu\)
ⓒ. \(Cu, Zn, Cd\)
ⓓ. \(Sc, Ti, Cr\)
Correct Answer: \(Sc, Ti, Cr\)
Explanation: \(Sc\), \(Ti\), and \(Cr\) each have atoms or common ions with incompletely filled \(d\)-subshells. That places them within the transition-element category. In contrast, \(Zn\), \(Cd\), and \(Hg\) are the standard exceptions among \(d\)-block elements because their common forms are \(d^{10}\). A set containing any of those exceptions cannot be a set of only transition elements.
20. Copper is regarded as a transition element mainly because
ⓐ. the neutral \(Cu\) atom has a \(d^9\) configuration
ⓑ. the ion \(Cu^{2+}\) has a \(d^9\) configuration
ⓒ. the ion \(Cu^+\) has an empty \(d\)-subshell
ⓓ. all common copper species are \(d^{10}\)
Correct Answer: the ion \(Cu^{2+}\) has a \(d^9\) configuration
Explanation: The atom of copper is \([Ar] 3d^{10} 4s^1\), so its \(d\)-subshell is filled in the neutral state. But the common ion \(Cu^{2+}\) has configuration \(3d^9\), which is incompletely filled. The definition allows a transition element to qualify through the atom or through at least one common oxidation state. This is why copper is included even though its neutral atom is not \(d^9\).
