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Read the passage given below and answer the following questions:
The transition elements have incompletely filled d-subshells in their ground state or in any of their oxidation states. The transition elements occupy position in betweens- and p-blocks in groups $3-12$ of the Periodic table. Starting from fourth period, transition elements consists of four complete series : Sc to $Zn, Y$ to Cd and La, $Hf$ to $Hg$ and $Ac, Rf$ to $Cn$. In general, the electronic configuration of outer orbitals of these elements is $(n - 1)d^{1-10} n^{1-2}$. The electronic configurations of outer orbitals of $Zn, Cd, Hg$ and $Cn$ are represented by the general formula $(n - 1)d^{10}ns^2$. All the transition elements have typical metallic properties such as high tensile strength, ductility, malleability. Except mercury, which is liquid at room temperature, other transition elements have typical metallic structures. The transition metals and their compounds also exhibit catalytic property and paramagnetic behaviour. Transition metal also forms alloys. An alloy is a blend of metals prepared by mixing the components. Alloys may be homogeneous solid solutions in which the atoms of one metal are distributed randomly among the atoms of the other.
The following questions are multiple choice questions. Choose the most appropriate answer:

1. Which of the following characteristics of transition metals is associated with higher catalytic activity?

1. High enthalpy of atomisation.
2. Variable oxidation states.
3. Paramagnetic behaviour.
4. Colour of hydrated ions.

2. Transition elements form alloys easily because they have.

1. Same atomic number.
2. Same electronic configuration.
3. Nearly same atomic size.
4. Same oxidation states.

3. The electronic configuration of tantalum $(Ta)$ is:

1. $[Xe]4f^05d^16s^2$
2. $[Xe]4f^{14}5d^26s^2$
3. $[Xe]4f^{14}5d^36s^2$
4. $[Xe]4f^{14}5d^46s^2$

4. Which one of the following outer orbital configurations may exhibit the largest number of oxidation states?

1. $3d^54s^1$
2. $3d^54s^2$
3. $3d^24s^2$
4. $3d^34s^2$

5. The correct statement(s) among the following is/ are:

1. All d and f-block elements are metals.
2. All d and f-block elements form coloured ions.
3. All d and f-block elements are paramagnetic.

1. $(I)$ only
2. $(I)$ and $(II)$ only
3. $(II)$ and $(III)$ only
4. $(I), (II)$ and $(III)$