The properties of non-metals are:

Iodine is an intensely colored solid with an almost metallic luster. This solid is relatively volatile and it sublimes when heated to form a violet-colored gas.

Chromite is an ore of chromium, bauxite is an ore of aluminium and tungston are metallic in nature while graphite is an allotrope of carbon and a carbonaceous compound. It is a very soft allotrope of carbon while other allotrope of carbon diamond is the hardest known element on this earth. This is because of the chemical structure of graphite which shows slippery nature of layers of carbon and presence of loose electrons.

Graphite is the most stable form of carbon and so it is used as the standard state for defining the heat and formation of carbon compounds. It has a layered planar structure and the bonding between the layers is vander waals bonds. It is a non metal with shining surface.

Non-metals do not have lustre. They do not reflect light from their surface. Non-metals have dull appearance. Diamond and iodine are two exceptions and are lustrous non-metal.

Non-metals do not have luster. They do not reflect light from their surface (exception diamond and iodine). Non-metals have dull appearance.

Silicon is a tetravalent metalloid. Pure silicon is used to produce silicon wafers in the semiconductor industry. Pure silicon is an intrinsic semiconductor as it conducts electron holes and increases electrical conductivity. Silicon is doped with other microelements to increas its conductivity. It is used in transistors, solar cells, semiconductor devices.

Plastic is waterproof, it cannot absorb water while the others can.

A silver glass mirror is an ordinary mirror, coated on its back surface with silver, which produces images by reflection. This kind of glass mirror is produced by coating a silver, copper film and two or more layers of waterproof paint on the back surface of float glass, which perfectly resists acid and moisture.

Non-metals are malleable, is an incorrect statement.

Bromine is a liquid non-metal. Rest others are metals.

Bromine is the only non-metal which is liquid and diatomic molecule at room temperature. 

Most of the non-metals are bad conductor of heat and electricity. But there are some non-metals which conduct electricity for example graphite. Due to presence of free electron in it.

Non-metals are not dense enough and do not have enough free electrons to pass electricity efficiently. Electrons in non-metals are held tightly , they are no allowed to move freely .

Oxygen is a non-metal. Non-metals do not have enough free electrons to pass electricity. Electrons in non-metals are held tightly, they are not allowed to move freely .

Non-metals vary greatly in appearance. They do not have lustre. As it does not have any free electrons light falling on non-metals does not reflect and hence non-metals are not shiny. Hence, they have a very dull appearance.

Diamond is the hardest substance known to man with a hardness of 10.0. It is brittle sometimes because it grows in diamond shape crystals, sometimes there are tiny cracks or flaws in the diamond and a hard strike against the crack of course will cause the diamond to crack into many pieces. Crystalline materials have planes of variable shear and normal strengths hence, they fail on fracture mechanism. Also, crystalline nature makes them extremely strong at surface resisting scratch.

Non-metals are very brittle and cannot be rolled into wires or pounded into sheets. They break easily when hit by a hammer.

Non-metal are neither malleable nor ductile. Non metals are brittle.

Non-metals are not ductile because they are brittle elements. They break easily. Such non-metals cannot be deformed by a hammer or rolling. 

Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. As it a non-metal, it cannot be deformed into a wire as it is brittle.

Iodine is a non-metal which is brittle in nature, it breaks and shatters easily when hammered. Hence, it cannot be used to make thin wires and is non-ductile.

Non-metals are non-malleable and non-ductile. They are brittle. They break easily. So, they are regarded as brittle. They can't be stretched into mines or hammered into sheets.

Brittleness is a characteristic property of non-metals. And here, we consider solid non-metals only. It is not applicable to liquid or gaseous non-metals.

Non metals do not have  lustre which means that non-metals do not have a shining surface. That means they have a dull appearance.

Non-metals are poor conductor of heat. So, they can't be used for cooking utensils.  

Hydrogen and helium are the two lightest gasses,  they weigh so less that helium balloons and hydrogen dirigibles are able to float in the atmosphere.

Carbon is the non-metal which conduct electricity in the form of graphite which is it's allotrope. Allotropes are the compound of the element in which they have same chemical properties but different physical properties. 

Semiconductors are the elements which conduct electricity but in less quantity. Hence, they are called as semiconductors.

Lustre means shine. Shining metals are also called lustrous metal. For example, gold. Non-metals such as sulphur, oxygen, nitrogen are non-lustrous but iodine is a greyish black solid and crystals have a metallic lustre.

All are metals in the given options iron, aluminium and copper but only carbon is a nonmetal present which is breakable with a hammer.

Non-metals have properties similar to that of metals , This  Statement is false because:

Properties of metals : 

Metals are solid at room temp. 
They are generally hard and strong. 
They have metallic lustre. 
They have high melting and boiling points. 
They are good conductors of heat and eletricity. 
Metals are sonorous. 
Most metals have high tensile strength. 
They are malleable. 
They are ductile. 
They have high densities. 


Properties for non-metals: 

Non-metals are glasses or solids at room temp. except bromine. 
They are not as hard as metals and have low tensile strengths. 
They do not have lusture. 
They are bad conductors of heat and electricity. 
Non-metals are brittle, they are neither malleable nor ductile. 
They usually have low densities. 
They have low melting and boiling points. 
They are non-sonorous. 

Zinc on heating with sulphur produces a greyish residue of zinc sulphide.
Sulphur is an element belonging to VI A group.
Sulphur is a nonmetallic element.

Amorphous or plastic sulfur is produced by rapid cooling of molten sulfur e.g. by pouring it in cold water. It has helical form and metastable at room temperature reverting to its crystal allotrope and have sharp melting point.

In case of iodine, the large size of the atom results in low shielding of valence electrons. 

Metals have high melting and boiling point. Tungsten has the highest melting point where as silver has low boiling point. Sodium and potassium have low melting points. Non metals have low melting point.

Graphite is able to conduct electricity, due to delocalization of the pi bond electrons above and below the planes of the carbon atoms. These electrons are free to move, so are able to conduct electricity.
In diamond, all four outer electrons of each carbon atom are 'localized' between the atoms in covalent bonding. The movement of electrons is restricted and diamond does not conduct an electric current.
Thus, graphite is a good conductor and diamond is not. 
Option "B" is correct.

Diamond and graphite are allotropes of carbon. Graphite has carbon molecules held together by weak van der Waal's forces of attraction and they have loosely bound electrons which are responsible for conducting electricity, while diamond is the hardest and strongest material in which all the molecules are bound by strong bonding between carbon tetrahedrons held by strong forces of attraction and so, they do not have free or loosely bound electrons to conduct electricity.

1) The glass is actually an insulator. 

2) It doesn't allow the flow of electrons easily from atom to atom, as seen in substances like copper, and other metals which are excellent conductors of both heat and electricity. 

3) Insulators have electrons that are held tightly which means they aren't shared between other atoms.

It's because going down the group the size of the atom increases because of the shielding effect due to which the interaction between the atom and the outermost electron decreases.

 So these electrons on the surface of iodine become excited by absorbing heat energy from light. so when they release this energy and come to their normal state, they emit this light so it appears that they have a shining surface.

So, the correct option is $C$

At room temperature liquid non-metal is bromine.

Graphite has a layered planar structure. Carbon atoms in the plane are bonded covalently with only three of the four potential bonding sites. The fourth electron is free to migrate in the plane making graphite electrically conductive.

Sulphur is a non-metal so it does not conduct electricity. Iron is a metal so it conducts electricity Magnesium oxide and Lithium fluoride are ionic compounds that contains ions which conducts electricity in molten state.

Its because going down the group the size of the atom increases because of shielding effect due to which the interaction between the atom and the outermost electron decreases so these electrons on the surface of iodine become excited by absorbing heat energy from light so when they release this energy and come to their normal state, they emit this light so it appears that they have lustrous surface.

1) Graphite is soft and slippery because there are only weak intermolecular forces between its layers. Graphite is a good conductor of heat and electricity.

2) Graphite can conduct electricity because of the delocalised (free) electrons in its structure.

3) These arise because each carbon atom is only bonded to 3 other carbon atomsHowever, in diamond, all 4 outer electrons on each carbon atom are used in covalent bonding, so there are no delocalised electrons.

4) These electrons in graphite are free to move through the structure.

It is a pale green gas and is used in cleaning products. Chlorine is an greenish-yellow gaseous element. Its atomic number is 17, and is one of the class called halogens in the periodic table. Large concentration of chlorine are dangerous.

Answer: all of the above 

Non-metals are non-malleable, non-ductile when they are beaten with hammer or stretched they break into pieces, so they are brittle.

When sulphur or phosphorus is stretched, they break into pieces. Non metals are non-malleable non-ductile.

Most of the solid non-metals are quite soft. For example - sulphur and phosphorous are solid non-metals which are quite soft.

Diamond and iodine both are non metal and lustrous.

Answer : $I^{\ominus}$

Electrical conductors elements have free electrons, which they can easily provide to conduct electricity. This characteristics are generally available in metals.

Carbon is a non-metal which have allotropic form that is graphite, diamond and fullerene. Out of this three only graphite is conductor of electricity. Diamond and fullerene do not conduct electricity.

The basic difference between metals and non-metals is the extent of bonding.Metals have very high extent of bonding than that in non-metals which makes the metal malleable. and non-metals brittle.

Non-metals are generally non-ductile and cannot be beaten into thin wires. All given elements $O,P,S$ are non metals and do not have property of ductility. 

$Hg$ is liquid at room temperature and cannot be beaten into thin wire; thus is not ductile at room temperature. All other metals $Cu, Sn ,  Pb$ are ductile at room temperature. 

Mercury and bromine both are present in liquid state at room temperature but mercury is metal and bromine is non-metal.

Sulphur extracted from natural sources is called brimstone. 

Wood is a good sound absorber. if it will be of some different material then there will be echo(a reflection of sound) in the hall and the sound will not be clear.

Prior to rubber tires, metal and wood were the materials in use. However it was found that natural Rubber provides better cushioning, makes less noise. Further rubber deforms under weight /force which results in larger contact patch with the road than with metal/wood tires of same diameter/width. During cornering at high speeds, the deformation of sidewall and larger contact area improves the traction or grip on the road increasing safety.

Valence band overlaps with conduction band for the conductivity of metal.

As we know that a needle and a knife both are made up of metals. 

Malleability is a substance's ability to deform under pressure ( compressive stress). If malleable, a material may be flattened into thin sheets by hammering or rolling. Malleable materials can be flattened into metal leaf. Many metals with high malleability also have high ductility.

$Ductility$ is when a solid material stretches under tensile stress. If a material is ductile it can be stretched into a wire. 

Silver is stable in pure water and air but tarnishes when it is exposed to air or water containing hydrogen sulfide, the latter forming a black layer of silver sulfide which can be cleaned off with dilute $HCl$.

Sodium and Potassium metals are the two metals which are soft and can be cut with a knife.

Most metals are solids because the intermolecular forces between the atoms of metals are quite large. This reduces the interstitial space and so they acquire a definite shape. Room temperature is not enough to provide them required kinetic energy to overcome their forces of attraction or convert its state. Thus, they remain solid at room temperature.

Greyish white metal which is a good conductor of electricity and heat and has a boiling point of $920^\circ C$ is zinc.

The metal Zinc has a melting point of $419^\circ C$.

A bar of zinc generates a characteristic sound when bent, similar to tin cry. A tin cry is the characteristic sound heard when a bar of tin is bent. Variously described as a "screaming" or "crackling" sound, the effect is caused by the crystal twinning in the metal.

• Traditional aqua regia is a mixture of concentrated nitric and hydrochloric acids in a ratio of 1:3 that can dissolve noble metals such as gold, platinum and palladium, even though the metals are not soluble in either acid alone.
  
• Hence option D is correct answer.
  

metallic character increases down the group and decreases along the period as we move left to right. Hence the order of increasing metallic character is 

There are no definitive chemical bonds between two metal atoms in a lattice. They all are held together by the so-called metallic bond. The valence electrons are not shared between metal atoms. Hence they exist as a single metal atom in their lattice unit. 

1) High melting and boiling point

2) Metallic bonding is the strong attraction between closely packed positive metal ions and a 'sea' of delocalised electrons.

3) The attraction between the metal ions and the delocalised electrons must be overcome to melt or to boil a metal.

4) These attractive forces are strong, so metals have high melting and boiling points.

Hardness of a metal is determined by the strong cohesive forces between the atoms. The cohesive forces between atoms of these metals are very weak. The bonding in these metals is weak and electrons are not located over a single atom but over a number of atoms. The weak bonding results in softness of metal.

Ans : (A) Metallic bonding can be described as an 'Electron Sea' with mobile valence Electron.

Ans : (A) Sample $A$ is metal

Molten silver absorbs oxygen which is given off on cooling causing violent spurting. This is called splitting of silver and can be prevented by covering the molten metal with a layer of charcoal.

The percent of silver in silver - copper alloy used for jewellery purposes has 80 % silver and 20% copper. Silver copper alloy is used in coins, ornaments, silver ware, decoration pieces, etc.

The following  are true regarding the physical properties of silver.
It is white, lustrous, heavy metal.
It is very malleable and ductile, coming next to gold in this property.
It is best conductor of heat and electricity.

Metal

The following are true regarding uses of silver.
Silver amalgam is used in filling teeth.
Silver leaves are used in Ayurvedic and Yunani medicines.
Silver is used in silver plating.
It is used in the preparation of silver salts used in silvering of mirrors, photography and medicine.

• A homogeneous mixture of two or more elements is known as Alloys.
• There are various alloys of copper:

Steel is an alloy of various metals, physically combined together in a fixed amount by weight, to improve the physical and mechanical properties.

The following are true about silver plating.
The process of depositing a thin layer of silver electrolytically on metal surface is called silver plating.
The article to be silver plated is made the cathode.
Anode consists of pure silver.
The bath contains a solution of potassium argentocyanide $(AgNO _3+ \text { excess of KCN})$

The metals which are placed high in the reactivity series are obtained by electrolysis, middle metals by reduction using carbon, lower by heating alone and metals at bottom of the series are found in native state.