Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
+1 vote
8.2k views
in S-Block Elements by (79.0k points)
recategorized by

Assertion: Helium and beryllium having similar outer electronic configuration of type  ns2

Reason : Both are chemically inert.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

1 Answer

+1 vote
by (76.3k points)
selected by
 
Best answer

Correct option (c) A is true but R is false

Explanation:

 Helium : Z = 2, 1s2

Beryllium =  Z = 4; 1s2, 2s2

Helium is an inert gas while beryllium is reactive due to unfilled 2p valence shells. 

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

...