Q.

Assertion (A) The elements having 1s2,2s2,2p6,3s2 and 1s2,2s2 configuration belong to same period.Reason (R) Both have same number of outermost shells.

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away
An Intiative by Sri Chaitanya

a

Both A and R are correct; R is the correct explanation of A.

b

Both A and R are correct; and R is not the correct explanation of A.

c

A is correct; R is incorrect.

d

R is correct; A is incorrect.

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

2p6,3s2⟶ Belongs to 3rd period1s2,2s2⟶Belongs to 2ndperiodBoth have ns2,valence shell electronic configuration, so both have same number of outermost shell.
Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon