Metals & non metals

Metals And

Nonmetals

There are 118 elements known at present . All elements can broadly classified as metals and nonmetals.A majority of elements are metals ,except mercury which is liquid at room temperature.There are 22 non metals :10- solid , 1 liquid i.e. bromine and 11 gases

INTRODUCTION

POSITION OF METALS AND NON METALS IN PERIODIC TABLE

The left hand side of periodic table and in the centre are placed the metals .

It may be noted that hydrogen (H) is an exception because it is nonmetal but placed on left side of the table.

The elements close to the zig zag line show the property of both metals and nonmetals . These are called metalloids. Commom example are Boron(B), silicon(S), germanium(Ge), arsenic(As), antimony(Sb).

POSITION OF METALS AND NON METALS IN PERIODIC TABLE

Continued Metallic character decreases from left

to right Increases from top to bottomLeft extreme are most metallic and

right extreme are least metallic.

All metals are solid at room temperature. Exception : Mercury (liquid)

Most metals are malleable i.e. can be hammered into thin sheets without breaking. Gold, Silver, Aluminum etc. are some highly malleable metals

Metals are ductile, it means metals can be drawn into thin wires. About 2 km length can be drawn from one gram gold.

Physical properties of metals

Metals are good conductors of heat. The conduction of heat is called thermal conductivity. Silver is the best conductor of heat. Lead is poorest conductor of heat . Mercury is also a good conductor

Metals are also good conductors of electricity . The electrical and thermal conductivities are due to presence of free electrons . Silver is again the best conductor of electricity. But since silver is expensive , therefore copper and aluminum are commmonly used.


Metals are lustrous. Metals have high densities. Eg.

Mercury has high density (13.6 g/cm3 ). Sodium and potassium are exceptions.

Metals are generally hard . Sodium and potassium are exception which can be cut with a knife

Metals have high melting and boiling points. Tungsten has the highest 34100C


Metals are rigid. Metals are sonorous.


When a metal has been kept exposed to air for long time, its appearance becomes dull due to formation of layer of oxide, hydroxide, carbonate of the metal by slow action of moisture and gases present in the air. This process is termed as corrosion. This the reason why further reaction between Al and air is not possible( though a thin layer of Al2O3 forms)

Why metal article on rubbing becomes brighter?

Non-Metals are brittle. Non-Metals are not ductile. Non-Metals are bad conductors of heat and

electricity(Except Graphite due to free electrons)

Non-Metals may be solid , liquid or gas at STP. Non-Metals are generally soft.(Exception:

Diamond) Non-Metals have low melting and boiling

points(Exception: Diamond and Graphite) Non-Metals have low densities( Exception:

Iodine).

Physical properties of non-metals

Metal atoms have usually 1,2 or 3 electrons in their outermost shells.These outermost electrons are loosely held by the nuclei.As a consequence they can easily loose electrons to form positively charged ions.

Na Na+ + e-

Mg Mg2+ + 2e-

Al Al3+ + 3e-

As a result metals are called electropositive elements.

Chemical Properties Of Metal

Metals react with Oxygen to form Metal Oxides.These oxides are basic in nature.When these oxides are dissolved in water they give alkaline solutions.

Eg:4Na + O2 2Na2O 2Na2O + H2O NaOH

Reaction With Oxygen

All metals do not react with Oxygen at equal ease.Reactivity with oxygen depends upon the nature of metal.

Reactivity of metals towards Oxygen:

1.Metals like Sodium, Potassium and Calcium react with Oxygen even at room temperature to form oxides. 4Na(s) + O2(g) 2Na2O(s)4K(s) + O2(g) 2K2O(s)2Ca(s) + O2(g) 2CaO(s)

2.Metals like Magnesium donot react with oxygen at Room temperature.They burn in air on heating to form correspondind oxides.2Mg(s) + O2(g) + Heat 2MgO(s) 3.Metals like Zinc react with oxygen only on strong heating.2Zn(s) + O2(g) + Heat 2ZnO(s)

4.Metals like Iron and Copper do not burn in air in strong heating. They react with oxygen only on prolonged heating.2Cu(s) + O2(g) + Heat 2CuO(s)3Fe(s) + 2O2(g) + Heat Fe3O4(s)

Metals react with water to form metal oxide/metal hydroxide and hydrogen.The reactivity of the metal depends upon the nature. 1. Sodium and Potassium react vigorously with cold water to form respective hydroxides and hydrogen gas is liberated. The reaction is so vigorously that hydrogen gas catches fire.2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)2K(s) + 2H2O(l) 2KOH(aq) + H2(g) 2. Calcium reacts with cold water to form calcium hydroxide but the reaction I less violent.Ca(s) + 2H2O(l) Ca(OH)2(aq) + H2(g)

Reaction With Water

3. Magnesium reacts very slowly with cold water but reacts rapidly with hot boiling water forming Magnesium oxide and hydrogen.Mg(s) + H2O(l) MgO(s) + H2(g) 4. Metals like zinc and aluminium react with steam to form oxides and hydrogen.Zn(s) + H2O(g) ZnO(s) + H2(g)2Al(s) + H2O(g) Al2O3(s) + 3H2(g)

5. Iron reacts with water only when steam is passed over red hot iron. The products are Iron(II,III) Oxide and hydrogen.3Fe(s) + 4H2O(g) Fe2O4(aq) + 4H2(g) 6.Metals like Copper, Gold and Silver do not react with water even under strong conditions.

1.Sodium, Magnesium and Calcium react violently with Hydrochloric Acid(HCl) or dilute Sulphuric Acid (H2SO4) liberating hydrogen gas and metal salt. 2Na(s) + 2HCl (aq) 2NaCl(aq) + H2(g)2Na(s) + H2SO4 (aq) Na2SO4(aq) + H2(g) 2.Alumunium and Zinc react with dilute HCl or dilute H2SO4 liberating hydrogen gas and corresponding metal salt. 2Al(s) + 6HCl (aq) 2AlCl3(aq) + 3H2(g)2Al(s) + 3H2SO4 (aq) Al2(SO4)3(aq) + 3H2(g)2Zn(s) + 2HCl (aq) ZnCl2(aq) + H2(g)2Zn(s) + H2SO4 (aq) ZnSO4(aq) + H2(g)

Reaction with Dilute Acids

3.Iron reacts slowly with dilute HCl or dil.H2SO4. Fe(s) + 2HCl (aq) FeCl2(aq) + H2(g) Fe(s) + H2SO4 (aq) FeSO4(aq) + H2(g) 4.Copper does not react with these acids. Fe(s) + HCl (aq) no reaction Fe(s) + H2SO4 (aq) no reaction Dilute Nitric acid(HNO3) is an oxidizing agent but doesnot produce hydrogen with metals.Exception in this case are Mg & Mn.

When a more reactive metal is placed in a salt solution of a less reactive metal,then the more reactive metal displaces the less reactive metal from its salt solution.Zn(s) + CuSO4(aq) ZnSO4 (aq) + Cu(s)However a less reactive metal cannot displace a more reactive metal.Cu(s) + ZnSO4(aq) no reactionMany metals react with dilute acids and liberate hydrogen gas. Only less reactive metals such as Copper, Silver, Gold etc. do not liberate hydrogen from dilute acids.

Reaction of metals with Salt solutions

Some metals are very reactive while others are very less reactive.On this basis they are arranged in decreasing order of their reactivities.This arrangement is called reactivity series.

REACTIVITY SERIES OF METALS

REACTIVITY SERIES OF METALS

In the series of metals, the basis of reactivity is the tendency of metals to lose electron. If a metal loses electron easily to form a positive ion (cation), it will react readily with other substances. Therefore it will be more reactive metal. Eg: Alkali metals like sodium and potassium are highly reactive metals.

Reasons for different Reactivities

All metals above hydrogen in the reactivity series(i.e. more active than hydrogen) like Zn,Mg,Ni etc. can liberate hydrogen from acids like HCl and H2SO4.These metals have greater tendency to lose e- from hydrogen.All metals below hydrogen in the reactivity series(i.e. Less active than hydrogen) like Au,Ag and Cu etc. cannot liberate hydrogen from acids like HCl and H2SO4.These metals have lesser tendency to lose e- from hydrogen. Therefore they cannot give electron to H+ ions.

Displacement of Hydrogen from Acids by Metals:

In general,a more reactive metal(placed higher in the activity series) can displace the less reactive metal from its salt solution.Eg: Zn(s) + CuSO4(aq) ZnSO4 (aq) + Cu(s)

Reactivity Series and Displacement Reactions:

According to octet rule “an atom whose outermost shell contains 8 electrons(octet) is stable.But in case of small atoms like He and H in which presence of 2 electrons in the outermost shell is considered to be the condition of stability.

Interaction Of Metals and Non-Metals

ELECTRONIC CONFIGUREATION OF SOME ELEMENTS

Atoms combine with another to form inert gas electron arrangement. An atom can achieve inert gas configuration in the following ways:I ) By losing one or more electronsII) By gaining one or more electrons III) By sharing one or more electronsNote : noble gases do not usually form bonds with other elements because they are stable.

Chemical Bonding (NaCl)

Chemical Bonding (CO2)

Chemical Bonding (Cl2, H2O, CH4, H2)

Ionic compound

formula

Ionic compound name

LiCl lithium chlorideNaCl sodium chlorideKCl potassium chlorideRbCl rubidium chlorideMgF2 magnesium fluorideMgCl2 magnesium chlorideMgBr2 magnesium bromideMgI2 magnesium iodide

Ionic compounds form crystals.Ionic compounds form crystal latticce rather than amorphous solids. Although molecular compounds form crystals, they frequently take other forms plus molecular crystals typically are softer than ionic crystals.Ionic compounds have high melting points and high boiling points.High temperatures are required to overcome the attraction between the positive and negative ions in ionic compounds. Therefore, a lot of energy is required to melt ionic compounds or cause them to boil.

Properties of ionic compounds

Ionic compounds have higher enthalpies of fusion and vaporization than molecular compounds.Just as ionic compounds have high melting and boiling points, they usually have enthalpies of fusion and vaporization that may be 10 to 100 times higher than those of most molecular compounds. The enthalpy of fusion is the heat required melt a single mole of a solid under constant pressure. The enthalpy of vaporization is the heat required for vaporize one mole of a liquid compound under constant pressure. Ionic compounds are hard and brittle.Ionic crystals are hard because the positive and negative ions are strongly attracted to each other and difficult to separate, however, when pressure is applied to an ionic crystal then ions of like charge may be forced closer to each other. The electrostatic repulsion can be enough to split the crystal, which is why ionic solids also are brittle.


Ionic compounds conduct electricity when they are dissolved in water.When ionic compounds are dissolved in water the dissociated ions are free to conduct electric charge through the solution. Molten ionic compounds (molten salts) also conduct electricity. Ionic solids are good insulators.Although they conduct in molten form or in aqueous solution, ionic solids do not conduct electricity very well because the ions are bound so tightly to each other.


ACTIVITY SERIES AND RELATED METALLURGY

All metals are present in the earth’s crust either in the free state or in the form of compounds. Aluminium metal is the most abundant metal I the earths crust. The second is iron and the third is calcium.

Occurrence of metals

The natural substance in which metals or their componds occur either in native state or combined state are called minerals.The minerals are not pure and contain different types of other impurities. The impurities associated with minerals are collectively known as gangue or matrix. The mineral from which the metal can be conveniently and profitably extracted is called ore.For example : aluminium occurs in the earths crust in the form of two minerals , bauxite(Al2O3.2H2O)and clay (Al2O3.2SiO2.2H2O). out of these two , aluminium can be profitably extracted from bauxite. Thus , bauxite is an ore of aluminium.

Minerals And Ores

The most common ores of metals are oxides, sulphides, halides, etc. Very unreactive are present I free state.Slightly reactive metals occur as sulphidesReactive metals occur as oxides.Most reactive metals occur as salts as carbonates, sulphates, halides,etc.

Types Of Ores

Element Element Ore Formula

Alluminium Bauxite Cryolite Corundum

Al2O3.2H2O Na3AlF6 Al2O3

Zinc Zinc blende Calamine Zincite

ZnS ZnCO3 ZnO

Iron

Haematite Magnetite Iron Pyrites Spathic Iron

Ore

FeO3 Fe3O4 FeS2 FeCO3

Copper Malachite Chalcopyrite Copper Glance

CuCO3•Cu(OH)2 CuFeS2 Cu2S

Sodium Rock Salt Sodium Carbonate

NaCl Na2Co3

Potassium Karnalite Salt Petre

KCl MgCl2.6H2 Na2Co3

Lead Anglesite Galena

PbCl2 PbS

Tin Tin Pyrites Cassiterite

Cu2FeSnS4 SnO2

Silver Silver Glance Ag2S

Steps in extraction of metal from ore

Based upon reactivity series metals can be grouped as follows:Metals of Low Reactivity:These metals are often found in free state in nature.Eg:Gold,Silver,Platinum Metals of Medium Reactivity:The ores of these metals are found mainly in oxides,sulphates and carbonates form.They are usually reduced using carbon.Eg:Zinc,Iron,Lead Metals of High Reactivity:Metals at the top of the reactivity series are never found in free state in nature.These are purified by electrolysis.

Extraction Of Metals:

Ores mined from earth are contaminated with large amount of impurities called gangue.The gangue is removed based on differences of physical and chemical particles of gangue and ore.

Enrichment Of Ores:

Metals low in the activity series are very unreactive. Their oxide ore can be reduced to metals by heating alone.Eg:Cinnabar(HgS) is an ore of mercury.It is first converted to Mercuric oxide which on further heating gives Mercury.Similar is the case for Copper too.The reactions involved are.For Mercury:2HgS(s)+3O2(g)+Heat 2HgO(s) + 2SO2(g) 2HgO(s) +Heat Hg(l) + O2(g)For Copper: 2Cu2S(s)+3O2(g)+Heat 2 Cu2O(s) + 2SO2(g) 2 Cu2O(s) + 2Cu2S(s)+Heat 6 Cu(s) + SO2(g)

Extracting Metals Low in the Activity Series:

Metals in the middle of the activity series are usually present in sulphides and carbonates. It is easier to obtain a metal from its oxide ore than sulphides or carbonates. The sulphide ores are converted to oxide ore by strongly heating in the presence of excess air. This process is known as roasting.Eg: 2ZnS(s) + 3O2(g)+Heat 2ZnO(s) + 2SO2 (g) (Roasting) The carbonate ore is strongly heated in the presence of limited air. This process is known as Calcination.Eg:ZnCO3 (s) ZnO(s)+ CO2(g) (Calcination) The metal oxides are then reduced to the metals using suitable agents such as carbon.Obtaining metals from their ores is a reduction process.Eg:ZnO(s) + C(s) Zn(s) + CO(g)

Extracting Metals Middle in the Activity Series:

The reactive metals such as Sodium, Calcium and Aluminium etc. are used as reducing agents because they can displace metals of lower reactivity to produce metals.Eg:3MnO2(s) + 4Al(s) 3Mn(l) + 2Al2O3 + HeatThe reactions are highly exothermic and hence the required metals are produced in liquid state.Eg:Fe2O3 (s) + 2Al (s) 2Fe(l) + 2Al2O3(s)+ Heat (Thermit Reaction-Used to join railway tracks or cracked machine parts)

The metals like Na,K,Mg,Ca,Al have more affinity to oxygen than carbon.Hence their oxides can’t be reduced.These metals are obtained only by Electrolytic reduction.These metals are obtained mostly from their halide ores.The metals are deposited at the cathode whereas the halogen at anode.Eg:At Cathode: Na+ + e- Na At Anode: 2Cl- Cl2 + 2e-

Extracting Metals at the Top of Reactivity Series:

The most widely used process for refining metals is electrolytic refining.Electrolytic Refining: In this process the impure metal is made the anode and a strip of pure metal the cathode.A solution of the metal salt is udes as electrolyte.On passing electricity,pure metal from anode dissolves into the electrolyte.An equivalent amount of metal from the electrolyte is deposited on the cathode.The soluble impurities go into the solution,whereas,the insoluble impurities settle down at the bottom and is known as anode mud.

Refining of Metals:

Corrosion is a natural process, which converts refined metal to their more stable oxide. It is the gradual destruction of materials (usually metals) by chemical reaction with their environment. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen.

Corrosion

PaintingOilingGreasingGalvanizingChrome PlatingAnodizingMaking Alloys

Prevention Of Corrosion

Galvanization is the process of protecting steel and iron from rusting by coating them with a thin layer of zinc.

Galvanization

An alloy is a material composed of two or more metals or a metal and a nonmetal. An alloy may be a solid solution of the elements (a single phase), a mixture of metallic phases (two or more solutions) or an intermetallic compound with no distinct boundary between the phases. It helps in prevention of corrosion.Stainless Steel is an Alloy of Iron along with small amounts of Manganese, Nickel, Chromium and Carbon.Brass ia an alloy of Copper and Zinc.Bronze is an alloy of Copper and Tin.If in an alloy one of the component is Mercury thn it is known as Amalgam.Solder is an alloy of Tin and Lead.

Alloys

Class & Section:10 B

Done By:Kazi Abeer

Science

Metals & non metals