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SAI International School
Subject-Chemistry

Ch-Is matter around us pure?
Topic- Pure & Impure substances, Elements, compounds & Mixtures,
Difference between elements, compounds and mixtures

Practice Worksheet
MCQs
Q.1 Copper is considered as an element because:
a) It is composed of same kind of atoms c) it is homogeneous
b) it is a pure substance d) all of the above.
Q.2 Which of the following statements about sugar is correct ?
a) It is composed of different types of particles
b) it is heterogeneous
c) it is has a fixed melting point
d) it is made up of carbon
Q.3 Which of the following statements about metals is incorrect?
a) they are lustrous d) they are ductile.
b) they are sonorous
c) they have low density

DIRECTION:Each of these questions contains an Assertion followed by Reason. Read
them carefully and answer the question on the basis of following options. You have to
select the one that best describes the two statements.

(a) If both Assertion and Reason are correct and Reason is the correct explanation of
Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of
Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.
(e) If Assertion & Reason both are incorrect.

Q.4. Assertion: Graphite has a shiny surface
Reason: Graphite is a non-metal.
Q.5. Assertion: All the particle of Magnesium are similar in all respects.
Reason: Magnesium is a pure substance.
Q.6 Water is made up of hydrogen and oxygen, yet it is considered as a pure
substance? Why?
Q.7 Explain why the compounds have fixed melting and boiling points.
Q.8 Give reasons: salt solution is a mixture not a compound.
Q.9 Sarthak took some iron filings and sulphur powder and mixed them. When he used
a magnet, he found that iron particles are attracted towards the magnet. On when he