Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q114 (CDS-II/2020) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Periodic table elements Answer Verified

The valency of phosphorus is ________.

Result
Your answer: —  Â·  Correct: D
Explanation

Phosphorus has an atomic number of 15, with an electronic configuration of 2, 8, 5. Since it has five electrons in its outermost shell, it can achieve stability by either gaining three electrons to complete its octet or by sharing its valence electrons [2]. In compounds like PF3, phosphorus is trivalent because it uses three of its five valence electrons for bonding. However, phosphorus can also expand its valence shell due to the presence of vacant d-orbitals, allowing it to utilize all five valence electrons. This results in a pentavalent state, as seen in compounds like PF5. Consequently, phosphorus commonly exhibits variable valencies of 3 and 5 [1]. While 3 is its standard valency based on the octet rule, 5 is achieved through hypervalence.

Sources

  1. [2] https://www.sciencedirect.com/topics/computer-science/valence-electron
  2. [1] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > 3.3 HOW DO METALS AND NON-METALS REA ALS REACT? > p. 47
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
50%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

NDA-II · 2025 · Q103 Relevance score: -0.78

Match List I with List II and select the answer using the code given below the Lists : List I (Element) A. Phosphorus B. Nitrogen C. Neon D. Sulphur List II (Atomicity) 1. 2 2. 1 3. 8 4. 4 Code : ABCD (a) 4 1 2 3 (b) 4 2 1 3 (c) 3 2 1 4 (d) 3 1 2 4

NDA-I · 2009 · Q95 Relevance score: -0.81

Two elements gallium and oxygen combine to form a compound Ga20 3. Which among the following is the valency of galluim?

CAPF · 2010 · Q21 Relevance score: -0.90

Which one of the following elements has valency three ?

NDA-II · 2016 · Q44 Relevance score: -0.91

Match List I with List II and select the correct answer using the code given below the Lists: List I (Element) A. Sulfur B. Phosphorous C. Lead List II (Highest Valency) I. Five 2 Six 3. Two D. Silver 4. Four Code: A B C 1)

NDA-II · 2012 · Q79 Relevance score: -1.20

Three elements Na, S and O combine to form a compound Na2SOg. What is the valency of S in this compound?