Lesson T7.1.1

T7.1.1 Mendeleev and the Periodic Table Quiz: KS3 Chemistry, Unit 7

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T7.1.1, Mendeleev and the Periodic Table: 20 multiple choice questions for the KS3 Chemistry (National Curriculum), Unit 7: The Periodic Table, written with Revision Ninja.

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The 20 questions

  1. What was the main arrangement principle used by Mendeleev for his Periodic Table?

    • Elements were ordered by colour of their compounds and their densities
    • Elements were ordered by their melting points, and then by their names
    • Elements were ordered alphabetically by their names in each row
    • Elements were ordered by relative atomic mass and grouped by similar properties

  2. Why did Mendeleev leave gaps in his Periodic Table?

    • To allow for undiscovered elements that would fit the pattern
    • To hold the elements that could not be measured accurately at the time
    • Because some elements were lost in the lab during early testing
    • Because the table was too small to fit every element that was known

  3. Mendeleev left a gap in his periodic table for an element he called eka-silicon. Which element was later discovered to fill this gap?

    • Germanium
    • Scandium
    • Phosphorus
    • Titanium

  4. Which tool did Mendeleev use to arrange the known elements?

    • A computer program that predicted the reactions of every element
    • A spectrometer that measured the atomic mass of each element
    • Cards with the properties of each element
    • A set of electrical circuits linked to a computer display

  5. What did Mendeleev notice about the properties of elements when they were arranged by atomic mass?

    • Properties were all identical once the elements were ordered
    • Properties got steadily more alike as the atomic mass rose
    • Properties repeated at regular intervals
    • Properties depended only on the colour of each element

  6. Which statement describes the modern Periodic Table?

    • Elements are arranged in order of atomic number
    • Elements are arranged in order of density only, from low to high
    • Elements are arranged in alphabetical order of their symbols
    • Elements are arranged in order of colour of their compounds

  7. What is the atomic number of an element?

    • The total number of particles in an atom
    • The number of neutrons in an atom
    • The number of electrons in a compound
    • The number of protons in an atom

  8. Mendeleev's Periodic Table placed tellurium and iodine in a particular order. What was the reason?

    • They were ordered by their colour, which matched the groups in the table
    • They were ordered by their melting points, which were very similar
    • They were ordered by the length of their names, to fit the gaps
    • Their properties fitted better in the table than their atomic mass order

  9. Which statement about Mendeleev's Periodic Table is correct?

    • It only listed gases and liquids, leaving out every solid element
    • It had no gaps at all, so it could not predict any element at all
    • It was rejected by every chemist of the time because of its many gaps
    • It was a useful tool for predicting properties of undiscovered elements

  10. Which feature of the Periodic Table shows the elements are arranged by their properties?

    • Elements with the same name in the same row of the table
    • Elements with the same density in the same column of the table
    • Groups of elements with similar properties in the same column
    • Elements of the same colour in the same row of the table

  11. Which information did Mendeleev rely on most when placing the elements?

    • The number of letters in each element's name and symbol
    • The date each element was first named by scientists
    • Chemical and physical properties of the elements
    • The country where each element was first found in the world

  12. Why was the Periodic Table an important development in chemistry?

    • It replaced the need for experiments in every area of chemistry
    • It showed how to make new elements from gases in a laboratory
    • It proved that elements cannot react with each other in any situation
    • It organised the elements into a pattern that predicted new elements

  13. Which statement best describes how the Periodic Table helps predict an element's properties?

    • Elements in the same colour have the same reactivity
    • Elements in the same group have similar properties
    • Elements in the same period have identical properties
    • Elements with the same name behave in the same way

  14. Which of these shows Mendeleev's work was based on patterns in properties?

    • Similar properties appearing at regular intervals in the table
    • Elements being arranged in order of their names in the table
    • Elements being sorted by their colour in each row of the table
    • Elements being placed randomly on a grid of equal squares

  15. Which statement best describes the role of the gaps in Mendeleev's table?

    • They showed where undiscovered elements should fit
    • They showed where elements had been removed from the table
    • They showed where the table had been damaged in transit
    • They showed where elements with no clear properties were placed

  16. Mendeleev predicted an element he called eka-aluminium. Which element was it later found to be?

    • Scandium
    • Boron
    • Gallium
    • Titanium

  17. Mendeleev predicted an element he called eka-boron. Which element was it later found to be?

    • Scandium
    • Gallium
    • Germanium
    • Yttrium

  18. Which scientist's predictions of undiscovered elements were later confirmed by discovery?

    • Rutherford
    • Faraday
    • Mendeleev
    • Dalton

  19. Why does the modern Periodic Table order elements by atomic number rather than atomic mass?

    • Ordering by atomic number makes the table colour-coded by group
    • Ordering by atomic number fixes the tellurium and iodine problem
    • Ordering by atomic number puts all the gases on the left side
    • Ordering by atomic number removes the need for any groups at all

  20. What is the name for the regular repeat of properties seen across the Periodic Table?

    • Periodicity
    • Isomerism
    • Ionisation
    • Oxidation

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