-
Engineering and Architecture
Exams
Colleges
Predictors
Resources
-
Computer Application and IT
Quick Links
Colleges
-
Pharmacy
Colleges
Resources
-
Hospitality and Tourism
Colleges
Resources
Diploma Colleges
-
Competition
Other Exams
Resources
-
School
Exams
Top Schools
Products & Resources
-
Study Abroad
Top Countries
Student Visas
-
Arts, Commerce & Sciences
Exams
Colleges
Upcoming Events
Resources
-
Management and Business Administration
Colleges & Courses
Predictors
-
Learn
Online Courses
Engineering Preparation
Medical Preparation
-
Online Courses and Certifications
Top Streams
Specializations
- Digital Marketing Certification Courses
- Cyber Security Certification Courses
- Artificial Intelligence Certification Courses
- Business Analytics Certification Courses
- Data Science Certification Courses
- Cloud Computing Certification Courses
- Machine Learning Certification Courses
- View All Certification Courses
Resources
-
Medicine and Allied Sciences
Colleges
Predictors
Resources
-
Law
Resources
Colleges
-
Animation and Design
Predictors & Articles
Colleges
Resources
-
Media, Mass Communication and Journalism
Colleges
Resources
-
Finance & Accounts
Top Courses & Careers
Colleges
Get Answers to all your Questions
(a) How is the valency of an element determined if its electronic configuration is known ? Determine the valency of an element of atomic no. 9.
(b) Given below are some elements of the Modern Periodic Table. Atomic numbers of the elements are given in parentheses : A(4), B(9), C(14), D(19), E(20)
(i) With the help of the electronic configuration, find out which one of the above elements will have one electron in its outermost shell.
(ii) Which two elements belong to the same group ? Give reasons for your answer.
(iii) Which one of the above elements belonging to the fourth period has bigger atomic radius and why ?
Answers (1)
An element's valency is determined by the number of electrons in its outer shell. Hence, the number of valence electrons obtained from the electronic configuration of the element gives the valency i.e. the number of electrons lost, gained or shared by the element to attain the noble gas configuration.
The valency of an element of atomic number 9 would be 1 since the number of valence electrons in its outermost shell is 7 so it needs only one electron to attain the noble gas configuration.
