Elements are classified as metals,non-metals,and metalloids. Give any one property of each. Also,give one example of each.

Write your observations when the following processes take place:
$(a)$ An aqueous solution of sugar is heated to dryness.
$(b)$ $A$ saturated solution of potassium chloride prepared at $60^\circ C$ is allowed to cool at room temperature.
$(c)$ $A$ mixture of iron filings and sulphur powder is heated strongly.
$(d)$ $A$ beam of light is passed through a colloidal solution.
$(e)$ $Dil. HCl$ is added to the mixture of iron and sulphur.

$(a)$ $7\, g$ of iron filings and $4\, g$ of sulphur powder is treated with dilute sulphuric acid at room temperature. Name the gas produced.
$(b)$ The same mixture is heated strongly,cooled and then treated with dilute sulphuric acid. Which gas would be produced?
$(c)$ What is the cause of this difference in results of chemical reaction in different conditions?

$(a)$ Name the separation techniques which you will apply for the separation of the following mixtures:
$(i)$ Small pieces of metal in the engine oil of a car.
$(ii)$ Fine mud particles suspended in water.
$(iii)$ Oil from water.
$(iv)$ Sodium chloride from its solution in water.
$(v)$ Camphor from salt.
$(vi)$ Wheat grains from husk.
$(b)$ Classify the following as a chemical or physical change:
$(i)$ Water boils to form steam.
$(ii)$ Burning of paper.
$(iii)$ An almirah gets rusted.
$(iv)$ Making a fruit salad with raw fruits.

What is meant by concentration of a solution?

Non-metals are usually poor conductors of heat and electricity. They are non-lustrous,non-sonorous,non-malleable,and are coloured.
$(a)$ Name a lustrous non-metal.
$(b)$ Name a non-metal which exists as a liquid at room temperature.
$(c)$ The allotropic form of a non-metal is a good conductor of electricity. Name the allotrope.
$(d)$ Name a non-metal which is known to form the largest number of compounds.
$(e)$ Name a non-metal other than carbon which shows allotropy.
$(f)$ Name a non-metal which is required for combustion.