Na, Mg and Al are the elements of the 3rd period of the Modern Periodic Table having group number 1, 2 and 13 respectively. Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximum chemical reactivity? Justify your answer stating the reason for each.
Na, Mg and Al are the elements of the 3rd period of the Modern Periodic Table having group number 1, 2 and 13 respectively. Which one of these elements has the (a) highest valency, (b) largest atomic radius, and (c) maximum chemical reactivity? Justify your answer stating the reason for each.
a) The valency of an element is the number of valence electrons present in the outermost shell of an atom of that element. The valency of Na is 1, Mg is 2 and Al is 3. Hence, Al has the highest valency among the given elements.
Marking Scheme
- 12 marks
Hint
The student should refer to the Modern Periodic Table and the properties of the elements in the 3rd period.
Quick Oral Answer
The student should be able to explain the properties of the given elements and justify their answers.
Analysis & Explanation
The question requires the student to analyze the properties of the given elements and justify their answers. The student needs to understand the concept of valency, atomic radius and chemical reactivity and how they are related to the position of an element in the Modern Periodic Table.
Common Mistakes
- 1confusing valency with atomic radius
- 2not considering the position of the elements in the Modern Periodic Table
Interesting Facts
The elements in the 3rd period of the Modern Periodic Table have different properties due to the difference in the number of valence electrons.
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2017?
This question carries 2 marks in the CBSE Class 10 Science 2017 examination.
Which chapter does this question come from in Science?
This question is from the chapter "Metals and Non-metals" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Metals and Non-metals" from CBSE Class 10 Science.
Has this question appeared in other CBSE Science papers?
Yes, a similar question appeared in the 2017 CBSE Class 10 Science paper.
What type of question is this in the CBSE Class 10 Science 2017 paper?
This is a Short Answer question from Section A in the CBSE Class 10 Science 2017 paper.