PYQPulse
HomeMocksPracticePYQsDashboard
PYQPulse

Timing-accurate mock tests and PYQs for SSC, Banking and Railway exams — so the real paper feels like a revision.

Exams

  • SSC exams
  • Banking exams
  • Railway exams
  • All exams

Practice

  • Practice questions
  • Mock test series
  • Sectional tests
  • Year-wise PYQs
  • Performance analytics

Company

  • About us
  • Help Centre
  • Pricing
  • Sign in

Legal

  • Privacy Policy
  • Terms of Service

Contact

  • hello@testwala.co.in
  • Telegram
  • +91 62816 87760

Practice interface modeled on the official exam pattern — not the official examination. PYQPulse is not affiliated with the Staff Selection Commission, IBPS, SBI, RBI, NABARD, SEBI or Indian Railways.

© 2026 PYQPulse. All rights reserved.

Built for aspirants, by aspirants.

HomeMocksPracticeStats
  1. Home
  2. ›
  3. PYQs
  4. ›
  5. TNPSC Group-I
  6. ›
  7. 2021
  8. ›
  9. Q51

TNPSC Group-I 2021 · Question 51 of 148

What are isotones?

Chemistry - Atomic Structure

  1. AAtoms have same number of protons but different number of neutrons
  2. BAtoms have same number of neutrons but different number of protonsCorrect
  3. CAtoms have same number of protons and neutrons
  4. DAtoms have same element with different masses

Answer: B. Atoms have same number of neutrons but different number of protons

Explanation

Isotones are atoms of different elements with the same number of neutrons but different numbers of protons.

Source: TNPSC Group-I Prelims (held 3 Jan 2021) - official paper via examrace.com

← Q50View full paper (148 questions)Q52 →

Practice the full TNPSC Group-I 2021 paper

Timed test with all 148 questions, just like the real exam.

Start test