Tc the element below Mn in the periodic table, would be expected to have high values for its :
(I) boiling point , (II) melting point
(III) density

Options

A. I, II, III
B. I, II
C. II, III
D. I only

Answer

To determine the expected values for the boiling point, melting point, and density of Technetium (Tc), which is located below Manganese (Mn) in the periodic table, we can analyze the factors affecting these properties step by step.

### Step-by-Step Solution:

1. **Understanding the Position in the Periodic Table**:
- Technetium (Tc) is located in Group 7 and Period 5 of the periodic table, directly below Manganese (Mn), which is in Group 7 and Period 4.
- As we move down a group in the periodic table, the atomic number increases, leading to an increase in the number of protons and electrons.

**Hint**: Consider how the position in the periodic table influences atomic structure and properties.

2. **Effective Nuclear Charge**:
- The effective nuclear charge (Z_eff) increases as we move down the group due to the increase in protons. This results in a stronger attraction between the nucleus and the electrons.
- A higher Z_eff leads to stronger metallic bonding in the element.

**Hint**: Reflect on how the number of protons affects the attraction between the nucleus and electrons.

3. **Atomic Size and Radius**:
- With an increase in protons, the atomic radius tends to decrease because the increased positive charge pulls the electrons closer to the nucleus.
- A smaller atomic radius means that the distance between the nucleus and the outermost electrons is reduced.

**Hint**: Think about how atomic size affects the properties of elements.

4. **Boiling Point and Melting Point**:
- The boiling point and melting point are influenced by the strength of the metallic bonds. As the effective nuclear charge increases and the atomic radius decreases, the strength of these bonds also increases.
- Therefore, both the boiling point and melting point of Technetium are expected to be higher than those of Manganese.

**Hint**: Consider how bond strength relates to phase changes like melting and boiling.

5. **Density**:
- Density is defined as mass per unit volume (Density = Mass/Volume). As the atomic mass increases (due to more protons and neutrons), and the atomic radius decreases, the volume of the atom decreases.
- Since the mass increases and the volume decreases, the density of Technetium is expected to be higher than that of Manganese.

**Hint**: Relate density to mass and volume, and think about how atomic structure influences these factors.

6. **Conclusion**:
- Based on the analysis, Technetium (Tc) is expected to have high values for its boiling point, melting point, and density due to the increased effective nuclear charge, stronger metallic bonding, and decreased atomic radius.

### Final Answer:
Technetium (Tc) would be expected to have high values for its:
- (I) Boiling point
- (II) Melting point
- (III) Density

Thus, the correct answer is option 1: all three properties are expected to be high.