CHAPTER 4 MATTER AND SUBSTANCE
1.1 Analysing Analysing changes in the states of matte 1.! Un"estan"ing the st#ct#e of an atom 1.$ A%%lying A%%lying the i"ea of %oton n#m&e an" n#cleon n#m&e in atoms of elements 1.4 Un"estan"ing the classification of elements in the Peio"ic Ta&le 1.' Un"estan"ing the %o%eties of s#&stances &ase" on the %aticles %esent in them 1.( Un"estan"ing the %o%eties an" #ses of metals an" non)metals 1.* Analysing metho"s of %#ifying s#&stances 1.+ A%%eciating A%%eciating the e,istence an" #ses of -aio#s s#&stances of "iffeent chaacteistics
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4.1 Analysing Changes Changes in the States of Matte inetic Theoy of Matte 1.
Matt Matter er is any anythin thing g tha thatt _________ ___________________ ____________________ ____________________ ___________________ _________
2.
The kineti kinetic c theor theory y of matter matter states states that.. that.... a) matte matterr is made made up of of _________ __________________ ___________________ ____________________ ___________________ _________
b) the particl particles es are constan constantly tly ___________________ _________ ____________________ ___________________ ____________________ _____________ __ c) ther there e are are _________ __________________ ___________________ _____________________ ____________________ ___________________ _________________ _______ d) partic particle les s have have ________ __________________ ____________________ ____________________ ___________________ ___________________ ______________ ____ e) as the tempera temperature ture increa increases ses _________ ___________________ ____________________ ___________________ ____________________ ___________ The Chaacteistics of Matte in the Soli"/ 0i#i" an" 2as States Chaacteistics Soli" 0i#i"
Aangement of the %aticles
Mo-ement of the %aticles 3oces of attaction &eteen the %aticles inetic enegy of the %aticles
Density
Sha%e
5ol#me
E,am%les
2
2as
Changes in the State of Matte
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4.! Un"estan"ing the st#ct#e of an atom Atomic St#ct#e We know that matter consists of ____________________________________ . The particles are known as ___________ An atom is made up of ______________________________________ __________________________________
De-elo%ment of the Atomic Mo"el
1!"!# $ohn %alton & %alton's atomic theory
1!(# $oseph $ohn Thomson & %iscovered electrons
1(11# *utherford & %iscovered the nucleus
1(+2# ,ir $ames -hadwick & %iscovered neutrons
S#&atomic Paticles) Poton/ Ne#tons an" Electons
1. There are three types of subatomic particles in an atom# i.e. protons# neutrons and electrons.
2. __________________________ make up the _____________________ in the centre. +. ___________ circle around the nucleus at a _________________________ called ___________
. The properties of subatomic particles are compared in t he table below. Po%eties
Electons
Potons
/ocation
The Movement
-harge *elative mass
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Ne#tons
The actual mass ,ymbol
4.$ A%%lying the i"ea of %oton n#m&e an" n#cleon n#m&e in atoms of elements Poton N#m&e an" N#cleon N#m&e in Atoms Poton N#m&e
N#cleon N#m&e
1. The atomic mass _________________________________________________________ in the atomic nucleus as _____________________________________________________________ 2. 0or an element# # the proton number and nucleon number can be represented.
The table below shows a few eamples of elements with their proton numbers and nucleon numbers.
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Element
N#cli"e
N#cleon
Poton
notation
n#m&e 6A7
n#m&e 687
Hy"oge
ne#tons
6987
6A ) 8 9 N7
H
2
He
3
Li
35
Chloine
electons
1
7
0ithi#m
N#m&e of
1
4
Heli#m
N#m&e of
17
Cl
:soto%e
1. 3sotopes are __________________________________________________________________ __________________________________
2. 3sotopes of the same element have _______________________________________________ _____________________
+. 4ygen has three isotopes# __________________________________ . The proton number is ____ but the three isotopes _____________________________________
. The diagram below shows the isotopes of hydrogen.
E,ecises 4.$
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1.
4.4 Un"estan"ing the classification of elements in the Peio"ic Ta&le All the elements must be classified and arranged in a proper way. ,cientists have arranged these elements based on their physical properties and chemical properties. Dmitri Mendeleev 5father of the periodic table6) had classified the elements according to ascending order of atomic mass. The 2o#%s an" Peio"s in the Peio"ic Ta&le
1. The periodic table has ____________ All the elements in each group have the _____________ 77777777777they have _________________________________________________________ 2. The ________________ in the periodic table are known as ________ . There are ___________ in the periodic table and the element of each period is arranged in _______________________ 777777777777777777777777777777777777777 +. All elements that are in the ____________________ have the __________________________ 777777777777777777777777777777777777777
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The :m%otance of the Peio"ic Ta&le The ________ in the ;;;;;;;;;;;;; can be divided into ________________________ namely _______________________________________
When ________________________________ / the elements vary.
1. ________________________
)
the
elements
change
from
__________________________
2. _____________ condition
&
the
elements
change
from
the
___________________________
+. 8lements
also
change
from
____________________________________________
4. _______________________________ E,ecises 4.4 St#ct#e" <#estion 1. %iagram 9 shows an incomplete periodic table.
5a) Among the elements represented by the letters :# ;# W# # < and =# state one element which
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being
5i) is a metal> 777777777777777777777777777777777777777777777777777777777777777777?1 mark@ 5ii) a non&metal> 7777777777777777777777777777777777777777777777777777777777777777?1 mark@ 5iii) a transition element>7777777777777777777777777777777777777777777777777777777777?1 mark@ 5b) ,tate one similarity between elements < and =. 777777777777777777777777777777777777777777777777777777777777777777777777777777777777 ?1 mark@ 5c) Which element has a proton number of +2 777777777777777777777777777777777777777777777777777777777777777777777777777777777777 ?1 mark@ 5d) The atom of element < has 2" neutrons in its nucleus. What is its nucleon number 777777777777777777777777777777777777777777777777777777777777777777777777777777777777 ?1 mark@
2. %iagram shows several eamples of metals from a group in the Beriodic Table.
8plain how you would develop a concept based on the information given in the diagram. 5a) 3dentify two common characteristics. 777777777777777777777777777777777777777777777777777777777777777777777777777 777777777777777777777777777777777777777777777777777777777777777777777777777 ?2 marks@ 5b) %evelop an initial concept. 777777777777777777777777777777777777777777777777777777777777777777777777777 ?1 mark@ 5c) Cive other eamples of elements in the same group. Cive eamples of elements with similar properties but belong to a different group. 777777777777777777777777777777777777777777777777777777777777777777777777777 777777777777777777777777777777777777777777777777777777777777777777777777777 ?2 marks@ 5d) 8plain the actual concept. 777777777777777777777777777777777777777777777777777777777777777777777777777 ?1 mark@
4.' Un"estan"ing the %o%eties of s#&stances &ase" on the %aticles %esent in them Matter consists of particles known as atoms. 8lements are substances that consist of atoms of one type only . Metals are substances made up of atoms held in place by strong forces of attraction called metallic bonds. Most non&metals form moleculesD a molecule consists of two or more atoms of the same type or of different types which are chemically combined together. ,ome metals combine with non&metals by transfer of electrons to form ionic compounds.
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Atom
1. An atom is the smallest particle of an element. 2. Most metals are made up of atoms of one type only and can eist on their own.
$. Atoms in metals are held by very stronq forces of attraction called metallic bonds. Molec#les
1.
A molecule
is a particle that is made up of two or more atoms that are combined
chemically. !. There are two types of molecules> a) molecules that have two or more atoms of the same type. 8amples> nitrogen molecules and oygen molecules
b) molecules that consist of two or more types of atoms. 8ample> ammonia molecules and water molecules
3.
There are weak forces of attraction between the molecules which are known as an der !aals forces.
. There is a group of solids known as covalent macromolecules which are held by very strong covalent bonds. Diamond and graphite are the best eamples of covalent macromolecules which are strong solids . ions 1. Atoms that lose electrons will become positively charged ions" while atoms that accept electrons will become negatively charged ions. 2. When sodium 5a metal) reacts with chlorine 5a non&metal) to form compound# the sodium atoms lose electrons to become positively charged ions" #a$. and chlorine atoms accept electrons to become negative ions. %& ' +. The ions are very stable and have strong electrostatic forces of attraction and have high melting and boiling points.
Physical Po%eties
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E,ecises 4.' Essay <#estion The electrical conductivity of substances made of atoms# substances made of molecules and substances made of ions are different.
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4.( Un"estan"ing the %o%eties an" #ses of metals an" non)metals There are many obEects that are made of metals. What are these obEects 8amples are screws# wrenches# keys# nails# and many more. W hat about non&metallic obEects 8amples of non&metals are paper# books# wooden desks# plastic cups and others.
The Po%eties an" Uses of Metals an" Non)metals
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Uses of Metal
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Uses of Non)metal Non Metal -arbon
Physical %o%ety an" #se -arbon eists in two forms of solid> diamond and graphite 5a) %iamond 5i) Fatural carbon is very hard. The carbon atoms in diamonds are bonded together using strong covalent bonds in a giant structure as shown in the figure below. 5ii) :ses> ( acts as a drilling bit for cutting stones and glass ( serves as e)pensive and beautiful *ewellery
5b) Craphite 5i) Craphite consists of layers of carbon atoms strongly bonded in the form of heagonal rings. 5ii) The layers of carbon are# however# weakly bonded to each other. As a result# they can move easily over one another. 5iii) Craphite can conduct electricity. 5iv) :ses> ( serves as a lubricant in machines ( for making pencil lead ( acts as a carbon electrode in a dry cell -lorine
5a) -hlorine is a poisonous gas which is yellowish green in colour. 5b) 3t dissolves easily in water to form hydrochloric acid and hypochlorous acid. 5c) :ses> +i, serves as a bleaching agent in detergents and in the paper industry +ii, for making organic solvents like chloroform and tetrachloromethane +iii, kills germs and cleans water in swimming pools and water purification
,ulphur 5a) ,ulphur is yellow in colour and burns easily. 5b) :ses> +i, for making sulphuric acid" paints and detergents +ii, for making anti'fungal drugs" synthetic fibres and matches +iii, added to natural rubber to produce vulcanised rubber +iv, for making solvents like carbon disulphide
Foble gas
5a) :ses>
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5i) Argon G for filling light bulbs 5ii) Feon G for filling advertising lamps and electronic appliances 5iii) Helium G for filling balloons 5iv) Irypton & to give out light of high intensity in light bulbs 5v) enon G for making anaesthetic drugs
E,ecises 4.(
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4.* Analysing metho"s of %#ifying s#&stances 17
P#e S#&stances 1. Bure substances contain atoms or molecules of only one type. 2. Bure substances have fi)ed melting and boiling points. +. The presence of impurities will lower the melting point but increase the boiling point of a substance. . The melting point of ice is "J-. The presence of impurities +e.g. salt, will lower the melting point by a few degrees depending on the quantity of salt added 5possibly &2J- or &+J-). K. -urified distilled water boils at 1""J- The presence of impurities 5e.g. salt) will increase the boiling point +probably 12/% or 10/%,.
Metho"s of P#ification 1. 3mpurities can be separated physically by the process of filtration" distillation and crystalliation. 2. How do you separate a miture of sugar and sand he mi)ture of sugar and sand is added with water so that all the sugar dissolves. hen the mi)ture is filtered. he insoluble sand will be left on the filter paper" and the filtrate +sugar solution, is collected. his process is called filtration. he sugar solution is then heated until it is saturated. hen the solution is left to cool and sugar crystals are formed. his process is called crystalliation. +. How do you get pure water from sea water 3ea water is heated to boiling at 1/%" the water vapour condenses in the iebig condenser and is collected. he water that condenses is known as the distillate +purified distilled water,. his process is called distillation. . When we want to separate a miture of two liLuids such as water and alcohol or petroleum components# fractional distillation can be carried out.
A%%lication of the Metho" of P#ification
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Water is a necessity of life in this world. Three Luarters of our world is covered with water. The problem the world is facing now is environmental pollution that has affected the supply of clean water for our daily use. *esearch has been carried out on various methods to get clean water.
A%%lications of P#ification The Brocess of 4btaining Burified %istilled Water 1. ,everal countries in the Middle 8ast have been distilling sea water to get drinking water. 2. Tap water is distilled etensively to get purified distilled water 5pure water). +. Burified distilled water is used in the preparation of chemical solutions and medicines in hospitals. . he water in the batteries of vehicles can also be replaced with distilled water.
The Pocess of =&taining P#e Clean Alcohol 3n the manufacture of alcohol# distillation is carried out to purify and increase the concentration of the alcohol.
3actional Distillation to =&tain Petole#m Com%onents
The Po"#ction of Salt Cystals ) Cystalli>ation 1. 8vaporation of sea water produces salt crystals. 2. ,ea water is passed into a large storage and left to evaporate in the ,un. +. After evaporation# the salt solution will be saturated" forming salt crystals
E,ecises 4.'
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Essay <#estion The boiling point of water increases when some salt is added into the water.
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4.+ A%%eciating the e,istence an" #ses of -aio#s s#&stances of "iffeent chaacteistics :nderstanding the characteristics and different conditions of different types of substances allows us to use the substances for different purposes. 3magine our lives without electricity# vehicles or anything which will make our lives easier. A%%eciating the E,istence of S#&stances Water 1. /ife on 8arth will not eist without water. 2. Water can eist in three states# i.e. the solid 5ice)# liLuid 5water) and gas 5water vapour). +. Water is used for cooking# drinking# washing# and as a solvent. . Water that flows in dams can generate hydro&electric power. Metal & Aluminium 1. Without aluminium aircraft may still be made of wood or other materials. 2. The strength of the aluminium alloy duralumin# which is light in nature is suitable for use in the manufacture of aircraft. +. Aluminium is used also in the manufacture of cooking utensils such as pots and pans because aluminium is a good conductor of heat. . Aluminium is a good conductor of electricity and is very suitable for use as cables for the transmission of electricity from the power plants to our homes.
E,am%les of coo?ing #tensils ma"e fom al#mini#m Metal & 3ron 1. 3ron metal is very strong and suitable for making steel used in the construction of bridges and buildings. 2. 3ron will rust. Therefore# when using iron to make car bodies or gates# iron must be painted to prevent rusting.
Fon&Metals 1. 4ygen is essential for living things to survive.
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2. 4ygen is reLuired for combustion. +. Betroleum is widely used as a fuel in the transportation industry and machinery in factories. 3magine how our lives will be without petroleum today . Many obEects that we use today are synthetic materials made from petroleum.
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