Lesson T2.1.2

T2.1.2 Atoms, elements and compounds Quiz: KS3 Chemistry, Unit 2

20 questions

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Lesson T2.1.2, Atoms, elements and compounds: 20 multiple choice questions for the KS3 Chemistry (National Curriculum), Unit 2: Atoms, elements and compounds, written with Revision Ninja.

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The 20 questions

  1. What is an element?

    • A substance made of particles that are always charged
    • A mixture of atoms that can be separated by filtration
    • A substance made of only one type of atom
    • A substance made of two or more types of atom chemically joined
  2. What is a compound?

    • A substance made of one element only, with all atoms of the same kind
    • A substance made of two or more elements chemically joined in a fixed ratio
    • A mixture of elements that can be separated by a magnet or by filtration
    • A solution of atoms dissolved in a liquid, which can be separated by evaporation
  3. Which of these is an element?

    • Water
    • Iron
    • Carbon dioxide
    • Table salt
  4. Which of these is a compound?

    • Oxygen
    • Copper
    • Gold
    • Water
  5. What is the difference between an atom and an element?

    • An element is always a gas, while an atom is always a solid made of the same material
    • An atom and an element are the same thing with different names used in different books
    • An atom is the smallest particle of an element; an element is a substance made only of such atoms
    • An atom is a substance; an element is a particle that is smaller than an atom, made of protons
  6. Which statement best describes the atoms in a compound?

    • They are always separated from each other by filtration in a laboratory
    • They are all atoms of the same element, joined together in a simple repeating pattern
    • They are simply mixed together without any chemical bonds holding them together
    • They are chemically bonded to atoms of other elements
  7. How can a compound be separated into its elements?

    • By a magnet, because the atoms in the compound are strongly metallic in nature
    • By evaporation, because the compound has no chemical bonds holding its atoms together
    • By a chemical reaction, because the bonds between atoms must be broken
    • By filtration, because the particles are too large to pass through the filter paper
  8. Why is a mixture of iron filings and sulfur not a compound?

    • Its parts always react together to form a gas, which can then be collected
    • Its parts are bonded together in a fixed ratio, so it is a single new substance
    • Its parts are not chemically bonded and can be separated by a magnet
    • It contains only one element, so there is no need to separate anything at all
  9. A substance is found to contain only carbon atoms. What is it?

    • An element
    • A mixture
    • A compound
    • A solution
  10. Which of these describes a compound?

    • A single atom of sodium surrounded by water
    • A mixture of sodium and chlorine atoms that are not joined
    • Sodium and chlorine atoms joined in a 1:1 ratio
    • Two separate samples of chlorine gas in one container
  11. Why is water a compound and not an element?

    • Its molecules contain only oxygen atoms, which are bonded in pairs in the liquid
    • Its molecules contain atoms of hydrogen and oxygen chemically joined
    • It is a liquid at room temperature, so it cannot contain any chemically bonded atoms
    • It can be separated into its parts by a magnet, which pulls the hydrogen away
  12. A student says air is a compound because it has oxygen and nitrogen in it. What is wrong?

    • Air is a mixture because its gases are not chemically joined
    • Air is a compound because oxygen and nitrogen are always bonded
    • Air is a solution of solid particles in water
    • Air is an element because it contains only one type of gas
  13. Which example shows a compound with properties very different from the elements that form it?

    • Carbon and oxygen always form a liquid at room temperature, which can then be poured
    • Hydrogen and oxygen always form a solid at room temperature when they are mixed
    • Iron and oxygen combine to form a gas that is always heavier than the air around it
    • Sodium and chlorine are dangerous, but the compound sodium chloride is table salt
  14. Which of these is a mixture rather than a compound?

    • Sodium chloride made by heating sodium in chlorine
    • Carbon dioxide formed by burning carbon
    • Water made by burning hydrogen
    • Sand and salt stirred together
  15. How many types of atom are present in an element?

    • At least three
    • Two
    • Only one
    • Exactly ten
  16. Which of these is a compound that contains three different elements?

    • Iron oxide, made of iron and oxygen only, in a fixed ratio of atoms
    • Calcium carbonate, made of calcium, carbon and oxygen
    • Brass, a mixture of copper and zinc that is not chemically bonded together
    • Carbon dioxide, made of carbon and oxygen only, in a ratio of one to two
  17. Which of these is correct about compounds?

    • A compound can contain any ratio of its elements, depending on how it is made
    • A compound always has the same ratio of its elements by mass
    • A compound can be split into its elements by filtration in the laboratory
    • A compound is always a solid at room temperature and cannot be poured
  18. Why can the atoms in a compound not be separated by a magnet like a mixture?

    • Atoms are chemically bonded, which needs a chemical reaction to break
    • Atoms in compounds are always liquid, so they flow away from the magnet
    • Atoms are too small to feel magnetic forces at all, even in a strong magnet
    • Atoms are made of electrons that repel magnets, so the magnet pushes them away
  19. Which of these describes atoms of an element reacting with another element to form a compound?

    • Atoms merge into a single larger atom of the same element as they react together
    • Atoms rearrange and form new bonds, making a new substance
    • Atoms mix physically and separate again with a filter in the laboratory
    • Atoms are converted into energy with no new substance, so the mass is lost
  20. Which pair includes an element and a compound?

    • Iron, an element, and steel, which is a mixture of iron with carbon
    • Copper, an element, and carbon dioxide, a compound
    • Air, a mixture of gases, and sea water, which is also a mixture
    • Water, a compound, and sea water, which is a mixture of many substances

All KS3 Chemistry quizzes