Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q47 (NDA-I/2021) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Periodic table elements Answer Verified

Which of the following sets of elements has the same valency?

Result
Your answer: —  Â·  Correct: D
Explanation

Valency is determined by the number of electrons in an element's outermost shell, which dictates its chemical bonding capacity [2]. Elements in the same group of the periodic table typically exhibit the same valency. Magnesium (Mg), Calcium (Ca), and Barium (Ba) all belong to Group 2, known as the alkaline earth metals [3]. According to their electronic configurations, Magnesium (2, 8, 2) and Calcium (2, 8, 8, 2) both possess two valence electrons, giving them a valency of 2 [3]. Barium, being further down in the same group, also shares this characteristic valency of 2 [3]. In contrast, Sodium (Na) and Potassium (K) are Group 1 elements with a valency of 1, while Aluminium (Al) is a Group 13 element with a valency of 3 [3]. Therefore, only the set Mg, Ca, and Ba has the same valency.

Sources

  1. [2] 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
  2. [3] https://www.energy.gov/sites/prod/files/2020/07/f76/The%20Periodic%20Table%20of%20Elements.pdf
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.
33%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

NDA-II · 2011 · Q32 Relevance score: 4.84

All the elements in a group (family) have a common valency. For example, all the elements of the carbon family (carbon, silicon, germanium, tin and lead) have common valency four. However, some of these elements can also have valency two. Which of the following can have valency two?

CAPF · 2010 · Q21 Relevance score: 3.81

Which one of the following elements has valency three ?

NDA-I · 2022 · Q13 Relevance score: 2.73

Which one of the following is the correct order of the valencies of elements Ne, Si, N and Mg ?

CDS-I · 2025 · Q53 Relevance score: 2.33

If atomic number of an element is 11, the correct name, symbol and valency are :

NDA-II · 2012 · Q79 Relevance score: 1.15

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