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Grade 10 Atomic Structure & Isotopes Worksheet with Answers

Grade 10 (US) · Year 11 (UK) · Class 10 (India) · Chemistry

Unit 1: Atomic StructureAtoms & IsotopesNGSS HS-PS1-1

Finding protons, neutrons and electrons from atomic number, mass number and charge. This free high school worksheet has 16 questions and a full answer key. Print it or save it as a PDF — every answer is checked by code, not guessed.

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Atomic Structure & Isotopes

Grade 10 · Chemistry

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Name

Class

Date

Learning goal: Atoms & Isotopes · NGSS HS-PS1-1

Directions: This worksheet has 2 parts. Read the instructions at the start of each part.

Example

How many electrons does a neutral atom of magnesium (atomic number 12) have?

Answer: 12

Part A

Label the diagram. Use the words in the box.

Word bank

protonnucleusneutronelectron
+++−−−−−−−−1234
  1. 1
  2. 2
  3. 3
  4. 4
Part B

Answer each question. Use full sentences where you can.

  1. 5

    Sulfur-32 has atomic number 16. How many neutrons does it have?

  2. 6

    An isotope of phosphorus (atomic number 15) has a mass number of 33. How many protons and neutrons does it have?

  3. 7

    Sodium-23 has atomic number 11. How many neutrons does it have?

  4. 8

    Fluorine-19 has atomic number 9. How many neutrons does it have?

  5. 9

    How many protons does an atom of fluorine (F, atomic number 9) have?

  6. 10

    Phosphorus-31 has atomic number 15. How many neutrons does it have?

  7. 11

    An isotope of argon (atomic number 18) has a mass number of 41. How many protons and neutrons does it have?

  8. 12

    An isotope of boron (atomic number 5) has a mass number of 14. How many protons and neutrons does it have?

  9. 13

    How many protons does an atom of lithium (Li, atomic number 3) have?

  10. 14

    How many protons does an atom of oxygen (O, atomic number 8) have?

  11. 15

    An isotope of silicon (atomic number 14) has a mass number of 29. How many protons and neutrons does it have?

  12. 16

    An isotope of potassium (atomic number 19) has a mass number of 41. How many protons and neutrons does it have?

★ Challenge corner for fast finishers

You are in a closed room with a candle, a match and a lamp. What do you light first?

How did I do?

Teacher's comments

Free printable worksheets with answer keys · aethelsystems.com/worksheets/chemistry/10/atomic_structure

Answer key (click to show)
  1. 1.nucleus
  2. 2.proton
  3. 3.neutron
  4. 4.electron
  5. 5.16
  6. 6.15 protons, 18 neutrons
  7. 7.12
  8. 8.10
  9. 9.9
  10. 10.16
  11. 11.18 protons, 23 neutrons
  12. 12.5 protons, 9 neutrons
  13. 13.3
  14. 14.8
  15. 15.14 protons, 15 neutrons
  16. 16.19 protons, 22 neutrons
  17. ★the match (challenge corner)

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