Nature of Matter: Elements, Compounds and Mixtures — Class 8 MCQs with Answers
Class 8 CBSE Science · Chapter 8
72 practice questions · 24 Easy · 24 Medium · 24 Hard · Updated
Practise the most important Class 8 CBSE Science questions from Chapter 8, "Nature of Matter: Elements, Compounds and Mixtures". You get 9 timed quizzes made from 72 NCERT-based MCQs, with answers and explanations. The questions are split into 24 Easy, 24 Medium and 24 Hard. Warm up on the basics, then move on to the exam-level questions that top scorers in CBSE Board exams get right.
To score well in "Nature of Matter: Elements, Compounds and Mixtures", focus on clear concepts in physics, chemistry and biology basics. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This helps you stay accurate when time is short, just as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Nature of Matter: Elements, Compounds and Mixtures, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 8 Science mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Nature of Matter: Elements, Compounds and Mixtures — important questions & MCQs with answers (Class 8 Science)
14 solved questions from this chapter's difficulty levels, each with its answer and explanation.
- Q1Easy
A mixture is made of:
A.two or more substances mixed together✓ CorrectB.only one substanceC.a single atomD.pure water onlyAnswer: A. two or more substances mixed together
Explanation: A mixture forms when two or more substances are combined without any chemical reaction between them, so each substance keeps its own identity.
- Q2Easy
An element is a pure substance that:
A.is a mixtureB.is made of many substancesC.cannot be broken down into simpler substances✓ CorrectD.is always a gasAnswer: C. cannot be broken down into simpler substances
Explanation: An element is the simplest form of matter — it cannot be split into any simpler substance by ordinary physical or chemical means.
- Q3Easy
A compound is formed when different elements combine:
A.chemically in a fixed ratio✓ CorrectB.just by mixingC.physically onlyD.neverAnswer: A. chemically in a fixed ratio
Explanation: A compound forms only through a chemical reaction where elements join in one fixed, unchanging ratio, unlike a mixture's variable proportions.
- Q4Easy
Common salt is obtained from salt water by:
A.using a magnetB.handpickingC.doing nothingD.evaporation✓ CorrectAnswer: D. evaporation
Explanation: Heating salt water evaporates the water, leaving the dissolved solid salt behind — a simple physical separation.
- Q5Easy
In a mixture, the substances:
A.become a new substanceB.keep their own properties and do not react chemically✓ CorrectC.always reactD.vanishAnswer: B. keep their own properties and do not react chemically
Explanation: In a mixture, no chemical reaction occurs, so each component keeps its original properties — unlike a compound, where a new substance with new properties forms.
- Q6Easy
Elements are made of only one kind of:
A.mixtureB.atom✓ CorrectC.compoundD.liquidAnswer: B. atom
Explanation: Every element consists of just one type of atom, which is what makes it a pure, unbreakable substance.
- Q7Medium
Air is a mixture because its gases:
A.keep their own properties and are not chemically combined✓ CorrectB.are chemically combinedC.form a compoundD.become a single elementAnswer: A. keep their own properties and are not chemically combined
Explanation: The gases in air, such as nitrogen and oxygen, remain chemically unchanged and retain their own properties, which is what makes air a mixture rather than a compound.
- Q8Medium
Oxygen and hydrogen are elements because they:
A.are mixturesB.are compoundsC.contain saltD.cannot be broken into simpler substances✓ CorrectAnswer: D. cannot be broken into simpler substances
Explanation: Oxygen and hydrogen qualify as elements precisely because no physical or chemical process can break them down into anything simpler.
- Q9Medium
Water can be broken into hydrogen and oxygen by an electric current, which shows water is a:
A.compound✓ CorrectB.elementC.mixtureD.single atomAnswer: A. compound
Explanation: Water can be broken into hydrogen and oxygen through electrolysis, and only a compound can be split into simpler substances this way — an element cannot.
- Q10Medium
To separate iron filings from a sand-and-iron mixture, you use:
A.a magnet✓ CorrectB.evaporationC.a batteryD.a lensAnswer: A. a magnet
Explanation: A magnet attracts the magnetic iron filings out of the mixture, leaving the non-magnetic sand behind.
- Q11Medium
A mixture can have its components in:
A.any proportion✓ CorrectB.only a fixed ratioC.a 2:1 ratio alwaysD.no proportionAnswer: A. any proportion
Explanation: Unlike a compound's fixed ratio, a mixture's components can be present in any proportion, since no chemical bonding fixes their amounts.
- Q12Hard
Which of these is NOT a pure substance?
A.oxygenB.waterC.salt water✓ CorrectD.ironAnswer: C. salt water
Explanation: Salt water is a mixture with variable composition, while oxygen, water and iron are all pure substances — elements or compounds.
- Q13Hard
Which list contains only elements?
A.iron, oxygen, copper, sulfur✓ CorrectB.water, salt, ironC.air, oxygen, ironD.sugar, water, oxygenAnswer: A. iron, oxygen, copper, sulfur
Explanation: Iron, oxygen, copper and sulfur are each made of only one kind of atom, so all four are elements; the other lists mix in compounds like water and salt.
- Q14Hard
Two substances A and B cannot be broken down further, and they combine to form C. Then:
A.A, B and C are all mixturesB.A and B are elements and C is a compound✓ CorrectC.C is an elementD.A and B are compoundsAnswer: B. A and B are elements and C is a compound
Explanation: Since A and B cannot be broken down further, they are elements by definition; their chemical combination C is therefore a compound.
Key concepts: Nature of Matter: Elements, Compounds and Mixtures (Class 8 Science)
This chapter classifies all matter. A mixture is two or more substances simply mixed together — its components keep their own properties, can be in any proportion, and can be separated by physical methods. A pure substance has just one kind of particle and is either an element or a compound. Elements are the simplest substances (one kind of atom, metals/non-metals/metalloids) and cannot be broken down. Compounds form when elements combine chemically in a fixed ratio to make a new substance with new properties, separable only by chemical means — as the iron-and-sulfur experiment neatly shows.
- Mixture
- Two or more substances mixed together whose components keep their own properties, are not chemically combined, and can be present in any proportion.
- Components of a mixture
- The individual substances that make up a mixture; they can be separated from one another by physical methods.
- Pure substance
- Matter made of only one type of particle, so all its particles behave identically; it is either an element or a compound.
- Element
- The simplest kind of pure substance, made of a single kind of atom, which cannot be broken down into anything simpler — the building block of all matter.
- Metals, non-metals, metalloids
- Elements are classified as metals (iron, copper, aluminium), non-metals (carbon, sulfur, hydrogen, oxygen) or metalloids, whose properties lie in between.
- Compound
- A pure substance formed when two or more elements combine chemically in a fixed ratio, giving a new substance with properties different from its elements.
- Fixed ratio
- The elements in a compound are always in a fixed ratio — hydrogen to oxygen in water is 2:1 and sodium to chlorine in common salt is 1:1.
- New properties of a compound
- A compound's properties differ from its elements: sodium (a reactive metal) and chlorine (a poisonous gas) form safe, tasty common salt.
- Mixture versus compound
- Iron filings and sulfur mixed can be separated by a magnet, but heating them forms iron sulfide, a compound the magnet cannot affect — a mixture is separable physically, a compound is not.
- Separating mixtures
- Choose a method to match a property: a magnet for iron, evaporation for dissolved salt, filtration for insoluble solids, and handpicking for large impurities.
- Alloys and minerals
- An alloy is a mixture of metals (like brass); a mineral is a natural solid with a fixed composition, usually a compound but occasionally a pure element.
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Start this chapter free →Nature of Matter: Elements, Compounds and Mixtures — FAQs
What are the key concepts in Class 8 Science Nature of Matter: Elements, Compounds and Mixtures?+
This chapter classifies all matter. A mixture is two or more substances simply mixed together — its components keep their own properties, can be in any proportion, and can be separated by physical methods. A pure substance has just one kind of particle and is either an element or a compound. Elements are the simplest substances (one kind of atom, metals/non-metals/metalloids) and cannot be broken down. Compounds form when elements combine chemically in a fixed ratio to make a new substance with new properties, separable only by chemical means — as the iron-and-sulfur experiment neatly shows. Key ideas include Mixture, Components of a mixture, Pure substance, Element, Metals, non-metals, metalloids, Compound.
What does Class 8 Science Chapter 8 (Nature of Matter: Elements, Compounds and Mixtures) cover on XamBaaz?+
It has 72 NCERT-based MCQs on "Nature of Matter: Elements, Compounds and Mixtures": 24 Easy, 24 Medium and 24 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE Board exams.
Are these "Nature of Matter: Elements, Compounds and Mixtures" questions free to practise?+
Yes. Sign in with Google to practise "Nature of Matter: Elements, Compounds and Mixtures" free. Full unlimited access is ₹999/year. One year from the day you pay. You stay in Class 8 till 31 March; on 1 April your account moves up to Class 9 and the rest of your year carries over. No chapter is charged separately.
How should I revise "Nature of Matter: Elements, Compounds and Mixtures" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Nature of Matter: Elements, Compounds and Mixtures" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Nature of Matter: Elements, Compounds and Mixtures" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Nature of Matter: Elements, Compounds and Mixtures (Class 8 Science)?+
The questions that matter most test Mixture, Components of a mixture, Pure substance, Element, Metals, non-metals, metalloids, Compound. This page shows 14 solved important MCQs with answers and explanations. Sign in to practise all 72 questions on the chapter as timed quizzes.
Is there an online quiz for Nature of Matter: Elements, Compounds and Mixtures?+
Yes — Class 8 Science Nature of Matter: Elements, Compounds and Mixtures has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.