Is Matter Around Us Pure Test - 1

Among the given options, only mercury is an element.
It is a metallic element.

Compounds are formed as a result of chemical reactions and do not display the properties of their constituent elements.

Glucose being a compound has unique properties of its own and does not exhibit the properties of carbon, oxygen or hydrogen.

A mixture is a material, which contains two or more different kinds of particles (atoms or molecules) which are physically mixed in any proportion, but not chemically combined. Mixture can be homogeneous or heterogeneous. Homogeneous mixture has a uniform composition. The components of homogeneous mixtures are not visible to the naked eye or even under a microscope. There are no visible boundaries of separation between the components of a homogeneous mixture, whereas heterogeneous mixtures are either visible to the naked eye or under microscope.

Mixture of sand and water has a non-uniform composition and the components of mixture (i.e. sand and water) are visible to naked eye. Therefore, it is a heterogeneous mixture.

Mixture of sugar and water is a homogeneous mixture having a uniform composition as sugar particles are small and dissolve completely in water.
Water is a compound made up of two elements, hydrogen (H) and oxygen (O), chemically combined in a fixed proportion of 1: 8 by mass. Water has a fixed boiling point of 100°C.

Sugar is also a compound and it has a fixed melting point.

Even though it is a mixture of immiscible liquids, the components will not separate out into layers because the dispersed phase, being particles of colloidal size will remain suspended.

However, centrifugation will cause the less dense component (in this case fat) to float on top.

Particles of a colloid can be separated by ultrafiltration but not by simple filtration as they are too small and pass through the holes of the ordinary filter paper.

Among the given options, blood is a colloid and its components can be separated by ultrafiltration but not by ordinary filtration.

The particles of the solute are small in size and have a small mass. Hence, the force of gravity acting on them is small and they do not settle down under the effect of their own weight, but remain in motion and maintain the uniformity of the composition by moving from their higher concentration to their lower concentration.

As a result, a solution is a homogeneous mixture.

Mass of solution is 100 g.
Percentage of salt in the solution = 30%

Amount of salt in the solution = 30 g
Amount of water in the sample = 100 - 30 = 70 g

The molecules of elements are made up of the same kind of atoms and are homonuclear. Ozone (O₃) is an element and is a homonuclear molecule; but water (H₂O), carbon dioxide (CO₂) and ammonia (NH₃) are compounds and are heteronuclear.