Chemistry 12th Edition

Published by McGraw-Hill Education
ISBN 10: 0078021510
ISBN 13: 978-0-07802-151-0

Chapter 8 - Periodic Relationships Among the Elements - Questions & Problems - Page 363: 8.92

Answer

Please see the work below.

Work Step by Step

As we know that $H^-$ and $He$ are isoelectronic species having two electrons. The nucleus of $H^-$ will attract two electrons less as compared to $He$. Hence, $H^-$ is larger.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.