The period number and group number of "Tantalum" (Z=73) are respectively:

Options

A. 5,7
B. 6,13
C. 6,5
D. None of these

Answer

To determine the period number and group number of Tantalum (Z=73), we can follow these steps:

### Step 1: Identify the Atomic Number
The atomic number of Tantalum is given as Z = 73.

### Step 2: Write the Electronic Configuration
To find the electronic configuration, we fill the orbitals according to the Aufbau principle. The electronic configuration for Tantalum is:
- Xenon (Xe) core: 54 electrons
- 4f subshell: 14 electrons (4f14)
- 5d subshell: 3 electrons (5d3)
- 6s subshell: 2 electrons (6s2)

Thus, the complete electronic configuration is:
\[ \text{Xe} \, 4f^{14} \, 5d^{3} \, 6s^{2} \]

### Step 3: Determine the Period Number
The period number corresponds to the highest principal quantum number (n) in the electronic configuration. In Tantalum's configuration:
- The highest principal quantum number is 6 (from the 6s subshell).

Therefore, the period number is **6**.

### Step 4: Determine the Group Number
To find the group number, we use the formula:
\[ \text{Group Number} = \text{Number of electrons in } ns + \text{Number of electrons in } (n-1)d \]

From the electronic configuration:
- The number of electrons in the 6s subshell (ns) = 2
- The number of electrons in the 5d subshell (n-1)d = 3

Thus, the group number is:
\[ \text{Group Number} = 2 + 3 = 5 \]

### Final Answer
The period number and group number of Tantalum are **6** and **5**, respectively.