Chapter 9, Problem 1AC

To determine

The incorrect statement regarding compoundsis:

A pure substance.

Composed of combinations of atoms.

Held together by chemical bonds.

A substance that cannot be broken down into simpler units.

Answer to Problem 1AC

Solution:

Option (d) is correct.

Explanation of Solution

Introduction:

The chemical substances which are composed of two or more atoms of different elements in a fixed ratio are called compounds. The elements are joined together by chemical bonds.

Explanation:

Reason for the correct option:

Compounds are the pure substances which are formed when two or more atoms of different elements are combined in a fixed ratio. The ratio of elements is the characteristic of a particular compound. The bond between atoms may be covalent or ionic bond. The constituents of compounds are separated by chemical methods.

Hence option (d) is correct.

Reasons for the incorrect options:

Option (a) is incorrect because a compound is a pure substance. It is not an incorrect statement about a compound. So, it is a wrong answer.

Option (b) is incorrect because compounds are formed when two or more atoms of different elements are combined in a fixed ratio. It is a correct statement about a compound. So it is a wrong answer.

Option (c) is incorrect because the elements in a compound are held together by chemical bonds. It is a correct statement about a compound. So it is a wrong answer.

Hence options (a), (b) and (c) are incorrect.

Conclusion:

By using the chemical methods, the constituents of compounds can be separated. Hence the statement “compound is a substance that cannot be broken down into simpler units” is not true for a compound.