keep it simple science 1 - metals

8/13/2019 Keep It Simple Science 1 - Metals

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CONCEPT DIAGRAM ("Mind Map") OF TOPICSome students find that memorizing the OUTLINE of a topic helps them learn and remember the concepts and

important facts. As you proceed th rough the topic, come back to this page regularly to see how each b it f its the

whole. At the end of the notes you will find a blank version of this "Mind Map" to practise on.

History of

Metal Use

Metal

Extraction

Needs Energy

Metal Reaction with

Oxygen

Water

Acids

The Activity Seriesof the Metals

MetalsWe Use

Today

Chemical Activity

of the

Metals

Electron Transfer

REDOX

Our Use of

Metals

Activity & Usage

of Metals

METALS

Patterns

of the

Periodic Table

History of the

Periodic Table

Extracting

Metals

from

Ores

QuantityCalculations

Definition

of the Mole

Conductivity

Melting Points Chemical Bonding

Valency

Reactivity

Atomic Radius1st Ionization

Energy

Electronegativity

Minerals

Ores

&

Resources

Case Study:

Extracting

Copper

from its Ore

Molar Ratios

in

Reactions

The Case for Recycling

Metals

Gay-Lussac's Law

&

Avogadro's Hypothesis

Mole Quantity

Calculations

Masses

Gas Volumes


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The First Uses of MetalsFor most of human existence, people used tools of stone,

wood and bone. Primitive tribes were familiar with gold

which occurs uncombined in nature, but it i s too soft to be

useful for anything but jewellery and decoration.

About 5,000 years ago, in the Middle East, some people

accidentally discovered that if certain rocks were roasted by

fire, small amounts of copper would be found later i n t he

ashes. Copper is too soft to be reallyuseful, but there was

a brief "Copper Age" around the eastern end of the

Mediterranean Sea. Copper was used for decoration,

jewellery, small utensils, and occasionally for knives and

spear points.

The big breakthrough was the discovery by these copper-

using people that if they roasted copper-bearing rocks

(ores) with tin ores, the resulting "alloy" (mixture) of

copper and tin produced a much harder metal, "bronze",

which could be cast in moulds, and hammered to shape

many useful tools and weapons ... this was the start of

The Bronze Age (approx 4,500 to 2,500 years ago)

It is no accident that the rise of the great ancient

civilizations occurred about this time. The stone blocks of

the pyramids and temples of ancient Egypt were cut and

shaped with bronze chisels. Egyptians, and later Greeks,

dominated their world because their soldiers were armed

with bronze swords, spears and arrowheads.

With bronze tools they built better ships and wagons for

transport and trade, which brought wealth and power.

Sad as it might be, t he f acts of human history are that

progress has been marked by conflict, war and conquest,

and metals have been a vital part of that development.

Metal has many advantages over stone, wood, or b one:

metal is harder, stronger, and flexible, not brittle.

metal can be cast, hammered or drawn into shapes not

possible in stone, such as saw blades, swords and armour.

when tools become blunt, metal can be re-sharpened.

Basically, a warrior with a bronze sword always beats a

bloke with a stone axe ... we call that progress!

The Iron Age (approx. 2,500 to 1,500 years ago)

About 1,000 B.C. the extraction of iron from its ores was

discovered. This requires much higher temperatures, and

t he br eakthrough was probably t he invention of t he

bellows, a device to pump air into afurnace so the wood or

charcoal burns hotter.

Iron is stronger and harder than bronze. A warrior armed

with iron weapons will usually beat a bronze-armed man.

Iron t ools and even the humble nail allowed new

developments in buildings, ships, wagons. .. remember that

towns, trade and commerce givewealth and power. An iron

plough allows more land to be cultivated to grow more

food, to feed a bigger army... and so on.

It is no accident that the dominant world power of this

time was ancient Rome, because their technology was

based on iron.

From the Medieval to the Modern

After the collapse of the Roman Empire the variouscultures that dominated the "Dark Ages" still had iron-

based technologies.

The next great technological change was the "Industrial

Revolution" which b egan about 1750 in England. This

had many aspects, but the big change in technology was the

use of coal (instead of wood) for fuel. As well as steam

engines, coal allowed for large scale smelting of iron and

the invention of steel (an alloy of iron with carbon).

The engines, tools and machinery of the great factories

were based on steel. Transport was revolutionized by steel

locomotives running on steel rails. Steel ships replaced

wooden ones, and steel weapons (machine guns, tanks and

artillery) achieved new heights (depths?) in warfare and

mass destruction.

In the 20th century, new metals and alloys became available...

aluminium, titanium, chromium, and many more.

This was made possible by electricity, which is needed in

large amounts to extract some metals from their ores, or to

purify and process them once extracted.

Human Progress has always been linked

to our use of Metals.

Progress in metal usage has always been linked

to the availability of energy to extract the metals.


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keep it simple science

The Metals We Use TodayIn one sense, we are still in the "Iron Age". Iron is still the

metal we use the most, but nearly always it is mixed with

other elements in a variety of alloys, notably steel.

Steel isused for bridges, tools and machinery, bolts, screws

and nails, reinforcing inside concrete structures, engines,

vehicle bodies, trains and their rails, ships, and "tin" cans.

Iron ore occurs in huge deposits, so iron is common and

economical to produce.

Steel (in its various forms) is very hard and strong.

It can be cast, milled, rolled, worked, bent, cut and

machined into just about any shape or size imaginable.

As always, our usage of the different steel alloys is linked to

their particular properties:

Steel Iron, Properties Uses

Alloy with ...

Mild steel 0.2% strong, but car bodies,

carbon malleable pipes, roofing

Tool steel 1-1.5% very hard drills, knives,

carbon hammers

Stainless 20% nickel resists food utensils,Steel & chromium corrOSIon, medical tools

hygenic

Brass

is a common "non-ferrous" (no iron) alloy.

Brass is very hard, but easilymachined for screw threads, etc.

It is more expensive than steel, but is corrosion resistant, so

it is ideal for taps and fittings forwater and gas pipes.

Solder

is an alloy of 30-50% tin with lead.

Its most notable property IS a very low melting point,

around 150-200C.

Its major use is in plumbing for sealing the joints between

pipes,. and in electronics for connecting small components

on a"circuit board".

Metals That Are Used in Their Pure State

Although we use a wide range of alloys, there are some

important metals we use in their pure, elemental state.

Aluminium

is very lightweight, yet strong and corrosion resistant

Its lightweight strength is perfect

for aircraft construction.

Lightweight and a good conductor,

it is used for electricity power lines.

Malleable and corrosion resistant, it

is ideal for window frames and drink cans.

Copper

is used for electrical wiring in building s and appliances,

because of its great electrical conductivity and its ductility

for ease of wire-making.

Metal Extraction Needs EnergyAs mentioned previously, our use of diff erent metals

through history can be linked to the availability of energy.

In topic 1, you learned about the process of chemical

decomposition; where a compound breaks down intosimpler substances.

Decomposition is generally an endothermic process;

energy is absorbed by the reactants during the reaction.

Generally, you must supply energy to make the process

happen.

Metal ores are mineral compounds. To obtain the elemental

metal involves decomposition, which is endothermic and

requires energy. Some compounds require more energy

than others for decomposition.

Copper and tin ores require little energy. A decent wood

fire can "smelt" the metal from its ore. TIllS why copper

and bronze were used in ancient times.

Iron ore requires more energy for decomposition. That's

why the "Iron Age" came later.

Aluminium and other "modern" metals require even more

energy, and electricity works better than heat, so these only

became available in quite recent times.


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Before metals, people used tools mainly madefrom a)............................. or .

The fIrst metal used was probably

b) , because it occurs i n the

elemental state in nature. However, it is too softto be used for tools, so was just used for

c) .

Metallurgy (the technology of metals) began withthe extraction of d) from ores

that were simply e) .

A big improvement was the mixing of ores of

f) and .

This produced the alloyg) ,

which made tools and weapons with many

advantages over stone: metal ish) and .

and isnot i) like stonemetal can made into intricate shapes, such as

j) : ,not possible in stone.

Later, bronze was replaced by k) .

which is1) and ,

but requires more m) for

its extraction.

During the "Industrial Revolution", the use of

n) for energy led to the production of

0) which is iron with a small

amount of p)................................ in it. This

allowed the development of machinery, trains

and the modern industrial world.

In the 20th century new metals such as

q) became availablebecause the

r) needed to extract it from its

s) was available.

Today,the metal weuse most is still t) ,in the form of the alloyu) Its

widespread useisbecause:

it is common and v) to

produce.

it is very w) and .

Steel comes in a variety of alloys, including

x) steel (car bodies, pipes, roofIng)

and y) steel used for foodutensils and medical tools.

Other alloys used widely include:

brass, amixture of z) and .

aa) , with a verylowmelting

point, is an alloy of ab) and

.................................... and is used in

ac) and .

As well as many alloys, there are some metalscommonly used in their pure, elemental form:

Aluminium, which has the advantages of beingad)................................. and resistant to

ae) .Uses include af) .

and .

ag) is used for electrical

wiring because of its good

ah) and because it is

ai) so it is easyto draw out into

wues.

Chemically, the extraction of metals from ores

involves aj) .

reactions, which are ak) -thermic. Some

metals, such as al).................................... require

very little energy, others such as

am) require muchmore. In many cases an) .

works better than heat in the extraction and

purifIcation processes. The changes in

ao) usage through history can be

directly linked to society's changing sources and

uses of ap) .

WHEN COMPLETED, WORKSHEETS

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Metals React With OxygenOne of the most familiar laboratory reactions 1S the

burning of magnesium:

Magnesium + Oxygen ~ Magnesium oxide

2 Mg + 0z ----.. 2 MgO

In fact, many metals will burn, some alot more readily and

violently than magnesium:

Sodium + Oxygen --.-4 Na + 0z --..

Sodium oxide

2 NazO

In these cases there is a violent exothermic reactio n, with

light and heat energy produced. The product is often a

powdery, crumbly solid.

Other metals, such as alumin ium and zinc, react on the

surface and the oxide compound formed is airtight and

pr~vents further reaction. That's why these metals are often

dull-looking ... the surface coat of oxide is dull.

Aluminium + Oxygen2Al + 30z

~ Aluminium oxide

----.. 2 AlZ03

Other metals, such as copper, react with oxygen very slowly

and only if heated strongly. Some, like gold, will not react

at all.

T he point is, that

metals have diff erent chemi cal activities.

Metals React With Water

Another favourite school reaction is when sodium reacts

with water. This is often done outdoors, because it results

in an exciting little explosion.

What happens is:

Sodium + Water ----.. Hydrogen(gas)

2 Na + 2 HzO . Hz

+ Sodiumhydroxide

+ 2NaOH

(In fact this is NOT the explosion reaction. The explosion

is the reaction of the hydrogen with oxygen, to f orm water)

Once again, some metals react easily and rapidly and form

the metal h)7droxide, while others react slowly if heated insteam, and form oxides.

Zinc + W ater ~ Hydrogen + Zinc oxide

Zn + HzO ~ Hz + ZnO

Metals W{ecopper and gold do not react at all.

There is an "Activity Series" among the metals.

Metals React With AcidsThe different activity levels of tl le metals is most clearly

seen when metals are reacted with dilute acids.

You may have done experimental work to observe howvigorously different metals react with a dilute acid.

Metals like calcium and

magnesium react vigorously.

When there is a reaction, the

gas produced ishydrogen.

The metal is "eaten away" and

dissolves into the liquid. This is

because it forms a soluble ionic

compound. Exactly what the

compound is, depends on which acid is used.

Zinc + H ydrochloric ~ Hydrogen + Zincacid chloride

Zn + 2HCI ~ Hz + ZnClz

Magnesium + Nitric ~ Hydrogen + Magnesiumacid nitrate

Mg + 2 HN03 ~ Hz + Mg(N03h

Iron + Sulfuricacid

Fe + HZS0

4

+ Iron(II)sulfate

+ FeS04

The ionic compounds formed are collectively known as

"salts", so the general pattern of the reactions is

I Metal + Acid

It will help you greatly to learn

the common laboratory acids

Common Name Chern Name

H yd ro chlo ri c Hyd ro gen c hlo ri de

SulfurIC Hydrogen Sulfate

Nitric Hydrogen nitr ate

Formula

HCI

HzS04HN03


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The Activity Series of the Metals

From these 3 patterns of reaction, i t seems there is a

further, underlying pattern. Certain metals, like sodium,

always seem to reac t readily and vigorously. Others, like

copper, always react slowly or not at all.

From this, aItd other reaction studies, the common

laboratory metals can be arranged in an "Activity Series":

Most

Active

Mg

AI

Ag

Au

Least

Active

The highly active metals all lie to the extreme left of the

table, AND the h igher their activity, the lower down the

table they are within each column.

This is one of many patterns that allows you to use the

Periodic Table instead of learning many small facts. For

example, instead of memorizing the Activity Series fully,

you can remember the pattern above and always be able to

figure out the order of the most active metals.

Northmead High School SL#603217

Electron Transfer in Metal Reactions

The chemical reactions that allow us to see the pattern of

the Activity Series are just part of an even greater pattern

in Chemistry ... the process of electron transfer.

To understand this, look again atthe reaction between a

metal and an acid:

Zinc + Hydrochloric ~ Hydrogen + Zincacid (gas) chloride

HCl and ZnClz are both ionic compounds. Here is the

equation re-written to show the individual ion "species".

IZn + 2B+ + 2Cr ------ B, + Zn +> + 2CrStudy this carefully and m ake sure you understand why

there have to be 2 of some ions to agree with the original

balanced equation.

Notice that the chloride ions (Clj occur on both sides of

the equation unchanged. Nothing has happened to them at

all. We say they are "spectator ions". Like by-standers at a

car crash they are not involved, while other atoms and ions

undergo serious changes.

Since they aren't actually i nvolved, we can leave the

spectators out. This is called a "net equation".

Now we can see what really happened;

a zinc atom became a zinc ion

and 2 hydrogen ions became a (covalent) hydrogen

molecule.

To do this, the zinc atom has to lose 2 electrons, and the

hydrogen ions must gain a pair of electrons to share.

Now it should be clear what reallyhappened: the zinc atom

gave a pair of electrons to some hydrogen ions. Electrons

were transferred from one "species" to another.

The equations above are "Half-Equations" and are often

used to describe what is reallyhappening in a reaction.


8/12


Oxidation and Reduction

The transfer of e lectrons from one species to another is

one of the most fundamental and important general

reactions of Chemistry.

The reaction between zinc and acid can be visualized like

this:

electrons transferred

~::;;::::~' G)

Zinc atom 2 Hydrogen ions

~

0;0I

Covalent bond(2 electrons being shared)

For historical reasons,

the loss of electrons is called "Oxidation"

The zinc oxidation allows the hydrogen to be reduced, and

the hydrogen reduction allows the zinc to be oxidized.

T he total reaction is an "Oxidation-Reduction" and is

commonly abbreviated to "REDOX".

Note that the syllabus does NOT r equire you to know

these defInitions yet, but it is worth knowing about Redox

for future topics. You ARE required to know about

electron transfer and " its involvement in metal reactions.

Northmead High School SL#60321 7

First Ionization EnergyAlthough you're not yet required t o kn ow ab out

Oxidation and Reduction, this bit you have to learn.

Definition

The Ionization Energy of an element is the energy

required to remove an electron from an atom.

For technical reasons, the measurement of this energyis carried out for atoms i n the gas state.

+----.- Zn (g) + e -

The energy required for this to happen is the

"1st Ionization Energy"

We know that zinc atoms normally lose 2 electrons to

form the Zn +2 ion. However, the formal defInition for

this process involves just the loss of 1 electron.

Every element has it s o wn characteristic value, eventhose elements which would not normally lose

electrons, such as non-metals like chlorine.

Normally a chlorine atom forms a negative ion

by gaining an electron.

Technically though, it is possible for it to lose

an electron if energy is added.

This energy is the "1st Ionization Energy"

Even the inert gases, which normally d o no t form ions

at all, can be forced to lo se an electron if energy is

added. They too have a 1st Ionization Energy value.

Ionization Energy Determines the Activity Series

Now back to the metals a n d the Activity Series.

In order for a metal to begin reacting with an acid, (or

with water or oxygen) it must lose an electron. Tlus will

require the input of its 1st Ionization Energy.

If the value for 1st Ionization energy is very low, the

metal will gain this energy easily and quickly from its

surroundings. It will readily enter the reaction, and the

reaction will proceed vigorously.

If its value for 1st IOluzation energy is higher, the atom

cannot react so readily or vigorously ... its activity is

lower.

The ACTIVITY SERIES of t he Metals

is determined by

1st IONIZATION ENERGY

K...Q)

c NaL.Uc

0

Li.~.~c

Ba.2

AIc

VI

rUZnQ)...

u

E

Fe

Sn

Ph

Cu

Ag

Au


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keep it s imple sc ience

Choice of MetalsBased on ActivitySometimes which metal is chose n fo r a p arti cular

application is based o n i ts position in the Activity Series.

Example

In critical electronic connections, su ch as computer

network pl ugs, it is essential that the electric signals get

through w itho ut loss or distortion.

Normally we us e copper for electrical winng, but in a

critical connection plug it is worth the extra expense of

using gold.

Copper is a low activity metal, but can slowly react with

oxygen to form a non-conducting oxide layer in the

connection. Go ld is l ower down the activity series and will

not react at all, s o the plug connection cannot corrode.

Gold's extremely low chemical activity (due to a relatively

high 1st Ionization Energy) is part of the reason it h as

always been used for jewellery.

Gold's low activity means it will not tarnish or corrode, so

it retains its beautiful colour and lustre.

Steel is cheap, but since iron

is about the middle of the

Activity Series it will

corrode (rust) by contact

with water. Is it better to

choose alower activity metal

such as copper, which will

not corrode as quickly, but is

more expensive?

The decision is usually to

use cheap steel pipes for

longer, outdoor uses like

your garden taps.

Indoors, where distances are

shorter, and a rusted-out

leaking pipe would b e a

disaster inside awall or

ceiling, copper is chosen,

especially for hot water

supply.

Interestingly, sometimes the higher activity metals corrode

less. Aluminiu m an d zinc are higher up the Activity Series

than iron. They react rapidly when exposed to oxygen, but

the surface layer of oxide is airtight and waterproof , and

prevents oxygen or water getting to the m etal underneath.

Therefore, these metals can be used in situations where

corrosion needs to be prevented.

"Galvanized" steel is coated with a thin layer of zinc to

prevent (or slow down) corrosion of steel roofIng, fence

wires, nails, bolts, etc.


10/12

When a metal reacts with oxygen it forms an a) .

compound.

I METAL + OXYGEN b) \

Some metals will also react with water, forming

c) gas and a d) .

compound.

I METAL + WATER --..c) + d) I

Most metals will react with acids, forming e) .

gas and an ionic compound called a ") "

I METAL + ACID ~ e) + ) ,

In all these reactions t he various metals react at

g) rates, showing an order of chemical

h) Fr om these reactions and others,

the "Activity Series" has been determined.

Metals such as i) and .

are the most active. These are the elements located in the

j) columns of the Periodic Table.

Some metals such as k) and .

have very low activity, and often do not react at all. Other

common metals like 1) and

.................................... are in t h e middle of the series. They

will react, but generally do s o m) .

All these reactions involve the transfer of n) .

In the case of the Metal + Acid reaction, the metal atoms

always 0)........................... electron(s) while a pair of

p) ions gain 2 electrons (which they

share in a q) bond) and form a

r) molecule with formula s) .

"Oxidation" is the technical term for t) .

................................. The opposite is "u) .

In the Metal + Acid reaction, the metal is alwaysv) while w) ions

are always x) .

The "1st y) Energy" of an element is

defined as the energy required to z) .

............................... from atoms in the aa) state.The very active metals are like that because they have very

ab) (high/low) values for tllls. Metals

further down the series do not react as vigorously because

their values are ac) .

Sometimes the choice of which metal to use is determined

by the activity level. An example is ad) .

1. Write a balanced, symbol equation for the reaction of

each of the following metals with oxygen.

a)Lead

(assume lead(IV) ion forms)

b) Iron

(Assume iron(III) ion)

2. a) Arrange the m etals in Q1 in or der of decreasing

chemical activity.

b) Which one(s), if any, might ignite easily and burn in

air with a visible flame?

3. Write a word equation AND a balanced, symbol

equation to describe the reaction of:

a) calcium metal with water (reacts spontaneously at room

temperature)

4. All the following equations are Metal + Acid reactions.Fill in all blank spaces, then re-write in symbols and

balance.

b) Calcium + Hydrochloric ~ + .acid

c) + ~ Hydrogen + Bariumnitrate

d) + ~ Hydrogen + iron(II)chloride

5. For each of the reactions in Q4, wlllch chemical species

a) lost electrons?b) gained electrons?

c) was a "spectator"?

WHEN COMPLETED, WORKSHEETS

BECOME SECTION SUMMARIES


11/12

Atomic Structure, Number and Mass

Here is a quick reminder of some basics about atoms you

need to know:

In the Nucleus are

Protons &

x'.," .Neutrons ..................... '"

;' :.' " ,- .. .

, '\.::/\,n DebitaeDund..... t he nucleus a re

the Electrons

E ach element's atoms have a different, characteristic,

number of protons and electrons. Therefore, each elementhas a different Atomic Number.

In the Periodic Table t he elements are arranged i n order of

Atomic Number.

No.Protons + No.Neutrons = "Mass Number"(Electron mass is insignificant)

The M ass N umber is always a whole number, but in the

Periodic Table the "Atomic Weight" is shown instead.

(How and why this i s different will be explained in a later

topic)

The Periodic Table

is firstly a list of the elements, arranged i n o rd er, a nd

showing all the basic details.

Atomic Number

18 Equal to the number of electronsand the number of protons in

each atom

ArArgon ..

"Atomic Weight"

NOT the "Mass Number"

The shape and arrangement of t he Periodic Table is a very

clever device to allow many patterns and grouping s to b e

accommodated. You have already learnt one pattern in the

position of the most active metals, and their 1st Ioniza tion

Energies.

History of the Periodic Table

The modern concept of a chemical element as a substance

containing identical atoms was first accepted almost exactly

200 years ago.

By 1830 there were about 40 known elements. Even with

such a small sample, people began to notice patterns:

Dobereiner (German) pointed out that there were several

groups of 3 elements witl1.remarkably sinlliar properties:

Lithium, sodium & potassiu m was one "triad".

Chlorine, bromine and iodine formed another "triad".

By 1860, with over 60 known elements, Newlands

(English) proposed a "Law of Octaves".

If the elements were arranged in order of r elative weights,

Newlands found that every 8th element (an "octave" ) was

sinlliar in properties. These similar elements included

Dobereiner's triads.

The s ystem worked well for the first 20 elements, but then

became confused.

The basis of the modern Periodic Table was developed by

the Russian, Dmitri Mendeleev in 1869.

Mendeleev used many physical and chemical properties:

atomic weight density

melting point formula of oxide compound

density of oxide and many more,

and arranged the elements in order of weight, but with

elements with sinlliar properties under each other.

Mendeleev's genius was to realiz t hat there were probably

missing elements that hadn't een d iscovered yet. He

cleverly lef t gaps in his table f or these undis covered

elements.

The most famous case was that of the "missing" element

Mendeleev called "eka-silicon" . He us ed the patterns in his

table to predict, very precisely, the properties for eka-

silicon. Scientists went looking for such a substance and

soon found a new element (which was named

"Germanium") with properties almost exactly as predicted.


12/12

Patterns of the Periodic Table

In Mendeleev's day no-one could explain why these patterns existed.

However, when scientists see patterns in nature like this, they know there must be underlying "r ules" or

"laws of nature" causing and controlling the patterns.

Perhaps Mendeleev's great contribution was not just the Periodic Table itself,

but the stimulus it gave other scientists to investigate the reasons behind the patterns.

Within 40 years Science had unravelled the secrets of atomic structure, the electron energy levels, and more.

At this s ta e our task is to lear n s ome of the atter ns.

Electrical Conductivity

As you go across any row ("period") of the table, you will

move through anumber of metals, then one or two semi-

metals, then into the non-metals.

Therefore, the conductivity will start out high, but r apidly

decrease as you encounter a semi-metal, and becomeextremely low at the non-metals.

r!, I

CLJ\ I i

llj~H~~tJTEI1:1

Boiling Points

follow a similar pattern to

Melting Points

Valencies are the same

down each group

Melting Point

You learned in topic 1 how melting point is determined by the

bonding within a substance.

At the left side of the table are the very active metals of d1e

Activity Series. They are also usually soft, and have relatively low

(for metals) melting points.

Moving to the right across a period you enter d1e "Transition

Block" containing typical hard, high melting point metals, held

strongly together by "metallic bonding".

Further right you hit d1e Semi-Metals. These often have very high

melting points because of their covalent lattice structure.

Then you enter d1e Non-Metals which have covalent molecular

structures and quite low mp's. At the far right column, each period

ends with an Inert Gas which are all s ingle-atom molecules, and

have d1elowest mp of each period.

This pattern repeats itself along each period.

Melting Points of ElementsIII

I

Peaks are Transi ti on M etals

or Semi-Metals

Sketch Graph.oooN

Go~ooo... -

c-

oc..

010

Nac

Chemical Bonding, Valency & Reactivity

What you've already learnt about the Activity Series, Ionic and Covalent Bonding and Valency

will help you make sense of the following: ("" G 8 I Group nert ases

No chemical reactions,

no bonding

Activity of Non-Metals

Most active at top-right(FIuori ne)

Activity (generally)decreases downwardsand to the left.

keep it simple science 1 - metals

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