📘 Detailed Solution
🔵 Step 1: Identify the Outer Configuration
The given outer electronic configuration is:
Here, the valence shell contains:
Therefore, the total number of valence electrons is:
🟢 Step 2: Determine the Group
For p-block elements, the general outer electronic configuration is:
ns²np² → Group 14
ns²np³ → Group 15
ns²np⁴ → Group 16
ns²np⁵ → Group 17
ns²np⁶ → Group 18
Since the given configuration is ns²np⁴, the element belongs to Group 16.
🎬 Valence Electron Calculation
🟣 Step 3: Examples
Elements having outer configuration ns²np⁴ belong to Group 16.
| Element | Outer Configuration | Group |
|---|---|---|
| Oxygen (O) | 2s²2p⁴ | 16 |
| Sulphur (S) | 3s²3p⁴ | 16 |
| Selenium (Se) | 4s²4p⁴ | 16 |
| Tellurium (Te) | 5s²5p⁴ | 16 |
🟠 Important Rule
For p-block elements, if the outer configuration is ns²npˣ, the group number is:
For ns²np⁴:
✅ Final Answer
An element with the outer electronic configuration ns²np⁴ belongs to Group 16 of the modern periodic table.
Example: Oxygen (2s²2p⁴)
📝 20 MCQs with Answers
1. The outer configuration ns²np⁴ belongs to which group?
✅ Answer
C) Group 16
2. How many valence electrons are present in ns²np⁴?
✅ Answer
C) 6
3. ns²np⁴ represents a:
✅ Answer
B) p-block configuration
4. Which element has the configuration 2s²2p⁴?
✅ Answer
C) Oxygen
5. Oxygen belongs to:
✅ Answer
C) Group 16
6. Sulphur has the outer configuration:
✅ Answer
C) 3s²3p⁴
7. Group 16 elements have how many valence electrons?
✅ Answer
C) 6
8. The p-block groups are:
✅ Answer
C) 13–18
9. The group number for ns²np¹ is:
✅ Answer
A) 13
10. The group number for ns²np² is:
✅ Answer
B) 14
11. The group number for ns²np³ is:
✅ Answer
B) 15
12. The group number for ns²np⁵ is:
✅ Answer
C) 17
13. The group number for ns²np⁶ is:
✅ Answer
C) 18
14. Which of the following belongs to Group 16?
✅ Answer
B) O
15. Group 16 is also known as:
✅ Answer
B) Chalcogens
16. An element with 6 valence electrons in the p-block belongs to:
✅ Answer
C) Group 16
17. Which configuration represents a Group 16 element?
✅ Answer
C) ns²np⁴
18. Selenium belongs to:
✅ Answer
B) Group 16
19. The general valence configuration of Group 16 is:
✅ Answer
C) ns²np⁴
20. For p-block elements, the group number of ns²np⁴ can be found by:
✅ Answer
B) 10 + 6 = 16
Q1. Identify the group of an element having outer configuration ns²np⁴.
Solution: It has 6 valence electrons. Therefore, it belongs to Group 16.
Q2. Give one example of an element having the configuration ns²np⁴.
Solution: Oxygen has the configuration 2s²2p⁴ and belongs to Group 16.
Q1. Determine the group of an element with outer configuration ns²np⁴.
Solution:
- Number of s electrons = 2.
- Number of p electrons = 4.
- Total valence electrons = 2 + 4 = 6.
Hence, the element belongs to Group 16.
Q1. Explain how the group of a p-block element is determined from its outer electronic configuration.
Solution:
| Outer Configuration | Valence Electrons | Group |
|---|---|---|
| ns²np¹ | 3 | 13 |
| ns²np² | 4 | 14 |
| ns²np³ | 5 | 15 |
| ns²np⁴ | 6 | 16 |
| ns²np⁵ | 7 | 17 |
| ns²np⁶ | 8 | 18 |
Therefore, ns²np⁴ → Group 16.
Q1. Explain the relationship between the outer electronic configuration and group number for p-block elements.
Solution:
The general outer electronic configuration of p-block elements is ns²np¹–⁶. The number of valence electrons determines the group number.
For ns²np⁴:
Thus, an element having the outer configuration ns²np⁴ belongs to Group 16.
Q1. Explain in detail how the group of an element with outer configuration ns²np⁴ is determined.
Solution:
The given outer electronic configuration is:
The element is a p-block element because the last electron enters a p-subshell.
The number of electrons in the outer shell is:
For p-block elements, the group number is obtained by adding 10 to the number of valence electrons:
Therefore, the element belongs to Group 16. Examples include oxygen, sulphur, selenium and tellurium.
ns²np⁴ → 6 valence electrons → p-block → Group 16.
🎯 Quick Revision
Valence Electrons = 2 + 4 = 6
Block = p-block
Group = 10 + 6 = 16
Example = Oxygen (2s²2p⁴)
