HelpContactFor teachers and institutes
>_StemPy Lab
Mock TestsClassesGroups

>_StemPy Lab

Learn. Solve. Code the solutions. Test yourself.

Live examsFree mock exams, timed and rankedEveryone starts together, and your score and rank come the moment it ends.See the exams →

Learn

  • Physics
  • Chemistry
  • Mathematics
  • Biology
  • Python Programming
  • Statistics & Data Science
  • Classes
  • Groups

Practice

  • Problems
  • Quizzes
  • Mock Tests
  • Question Sets
  • Exams
  • Certificates
  • Python Labs
  • AI Practice Generator
  • Student-Created Tests

Community

  • Discussions
  • Resources
  • Notes
  • Blog

Account

  • Dashboard
  • My Content
  • Profile
  • Log in
© 2026 senLearn. All rights reserved.HelpAboutContactPrivacy PolicyTerms of UseRefund Policy
  1. Problems
  2. /Structure of the Atom
  3. /Isotopes and Isobars

Isotopes and Isobars

Chemistry
+ Upload a Problem
More in Structure of the AtomSubatomic Particles and Atomic ModelsElectronic Configuration and ValencyIsotopes and IsobarsLight, Atomic Spectra and the Bohr ModelQuantum Mechanical Model of the Atom
16 problems
Type:
1.
Rubidium has two isotopes, ⁸⁵Rb and ⁸⁷Rb.
High School (11–12) · Isotopes and Isobars, Subatomic Particles and Atomic ModelsStemPy LabStemPy Lab
Medium
2.
Singly charged ions of boron-10 and boron-11 are accelerated through the same voltage and enter the…
High School (11–12) · Isotopes and Isobars, Subatomic Particles and Atomic ModelsStemPy LabStemPy Lab
Medium
3.
Find the numbers of protons, neutrons and electrons in ³²₁₆S²⁻, ²⁴₁₂Mg²⁺ and ¹⁹₉F⁻.
High School (11–12) · Isotopes and Isobars, Subatomic Particles and Atomic ModelsStemPy LabStemPy Lab
Easy
4.
Match each isotope with its use. Isotopes: (1) uranium-235, (2) cobalt-60, (3) iodine-131, (4)…
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Easy
5.
Calcium-40 has Z = 20, and argon-40 has Z = 18.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Easy
6.
Silver has two isotopes. One has a mass number of 107, and it is 52 % of the atoms.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Hard
7.
Copper has two isotopes, with mass numbers 63 and 65.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Medium
8.
Natural lithium is mostly lithium-7. For some special uses, lithium is enriched, so that it is 30 %…
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Medium
9.
Natural boron is 20 % boron-10 and 80 % boron-11, with an average atomic mass of 10.8 u.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Easy
10.
Five atoms are given as (Z, A): P (6, 12), Q (6, 14), R (7, 14), S (8, 16) and T (8, 18).
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Medium
11.
Water can be made with the heavier isotopes of hydrogen: deuterium, ²₁H (D), and tritium, ³₁H (T).
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Medium
12.
Atom X has 17 protons and 18 neutrons. Atom Y has 17 protons and 20 neutrons.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Medium
13.
Carbon has the atomic number 6. Find the number of neutrons in carbon-12, carbon-13 and carbon-14.
High School (9–10), General · Isotopes and IsobarsStemPy LabStemPy Lab
Easy
14.
Lithium-7 has an atomic number of 3. The lithium ion, Li⁺, has a charge of +1.
High School (9–10), General · Electronic Configuration and Valency, Isotopes and IsobarsStemPy LabStemPy Lab
Medium
15.
An atom has 19 protons and 20 neutrons. The element is potassium, K.
High School (9–10), General · Electronic Configuration and Valency, Isotopes and IsobarsStemPy LabStemPy Lab
Easy
16.
Sulphur has an atomic number of 16. Find the number of protons, neutrons and electrons in a neutral…
High School (9–10), General · Electronic Configuration and Valency, Isotopes and IsobarsStemPy LabStemPy Lab
Easy