Assertion (A): Mixtures are impure substances made up of two or more kinds of elements and compounds mixed together in any proportion.

Reason (R): Homogeneous mixtures have a uniform composition throughout their bulk.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): All compounds contain more than one type of element in their molecules.

Reason (R) : Compounds can be homogeneous or heterogeneous.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Chromatography is the latest technique to separate the components of a mixture when all the components are different in their properties.

Reason (R): Components of ink are separated by chromatography.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Fill in the blanks:

(a) Brass is a solid-solid …………… mixture.

(b) The method used to separate sawdust and sand is …………… .

(c) Kerosene oil and water are …………… liquids.

(d) Atomicity is the number of atoms in a molecule of …………… .