Is Matter Around Us Pure - 2 - Free MCQ Practice Test with solutions, UPSC

A substance that can be beaten into thin sheets and drawn into thin wire is both malleable and ductile. Gold is most malleable and ductile element.

Mixtures are one product of mechanically blending or mixing chemical substances such as elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup.
A chemical compound is a substance composed of two or more different elements chemically bonded together in a fixed proportion by mass. However, not all molecules are compounds. Compounds are pure substances that contain two or more elements combined in a definite fixed proportion.
Any substance that contains only one kind of an atom is known as an element. Because atoms cannot be created or destroyed in a chemical reaction, elements such as phosphorus (P4) or sulfur (S8) cannot be broken down into simpler substances by these reactions.
When a molecule is formed from elements of a different species it is a heteroatomic molecule. As an atom is the smallest particle of an element that retains the properties of that element, a molecule is the smallest particle of a compound.

Clouds and fogs are example of liquid in gas solution. Cloud is formed by combination of water vapour with dust particles. Fogs contain water vapour and gases.

Scattering of beam of light when passes through a solution is called tyndall effect. Colloidal solution shows the tyndall effect and scatter the beam of light.

Hydrogen sulfide gas produces an offensive "rotten egg" or "sulfur water" odor and taste in the water. In some cases, the odor may be noticeable only when the water is initially turned on or when hot water is run. Heat forces the gas into the air which may cause the odor to be especially offensive in a shower. Occasionally, a hot water heater is a source of hydrogen sulfide odor. The magnesium corrosion control rod present in many hot water heaters can chemically reduce naturally occurring sulfates to hydrogen sulfide.

The liquid which contains some suspended particles are called suspension. The size of particle is more than 100nm.

There are 92 naturally occurring elements. These elements exist in nature and are not artificially created. Here are some key points about these elements:

• The majority of elements are solid.
• Eleven elements are gases at room temperature.
• Two elements, mercury and bromine, are liquid at room temperature.
• Elements such as gallium and cesium become liquid just above room temperature.

In addition to the naturally occurring elements, there are also man-made elements, which are typically created in laboratories or nuclear reactors.