Element with atomic number 17 has its place in periodic table

Options

A. III period, VIl group
B. VIl period, VIl group
C. IV period, VIl group
D. II Period, VI group

Explanation

To determine the position of the element with atomic number 17 in the periodic table, we can follow these steps:

### Step 1: Identify the Element
The element with atomic number 17 is Chlorine (Cl).

### Step 2: Determine the Electronic Configuration
The electronic configuration of Chlorine can be calculated as follows:
- The atomic number 17 means there are 17 electrons.
- The distribution of these electrons in shells follows the order: K, L, M.
- The electronic configuration is:
- K shell: 2 electrons
- L shell: 8 electrons
- M shell: 7 electrons
- Therefore, the electronic configuration is \( 2, 8, 7 \).

### Step 3: Determine the Number of Shells
The number of shells corresponds to the number of energy levels filled with electrons:
- K shell (1st shell) = 2 electrons
- L shell (2nd shell) = 8 electrons
- M shell (3rd shell) = 7 electrons
- Total shells = 3 (K, L, M)

### Step 4: Identify the Period
The number of shells indicates the period:
- Since there are 3 shells, Chlorine is in the 3rd period of the periodic table.

### Step 5: Determine the Valence Electrons
Valence electrons are the electrons in the outermost shell:
- For Chlorine, the outermost shell (M shell) has 7 electrons.
- Therefore, Chlorine has 7 valence electrons.

### Step 6: Identify the Group
The group number is determined by the number of valence electrons:
- Since Chlorine has 7 valence electrons, it belongs to Group 17 (or Group VIIA in older nomenclature).

### Conclusion
Thus, the element with atomic number 17 (Chlorine) is located in the 3rd period and Group 17 of the periodic table.

### Final Answer
Chlorine (Cl) is in the 3rd period and Group 17 of the periodic table.

---