2 Group 18 Elements Updated Student

8/8/2019 2 Group 18 Elements Updated Student

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PERIODIC TABLE OF ELEMENTS

B. GROUP 18 ELEMENTS

1. The elements in Group 18 are

Helium ______Neon __________

Argon ______Krypton _______

Xenon ___________

Radon ___________

2. They are also known as________________, which arechemically_____________. Noble gases are____________.

3. Helium has_____ valence electrons. This is called_________electron arrangement.

4. Other noble gases have_________ valence electrons. This iscalled__________ electron arrangement.

5. Duplet and octet electron arrangements are very_________because the______________________.

6. All nobles gases are_________ which means chemicallyunreactive.

BECAUSE THE OUTERMOST OCCUPIEDSHELLS ARE FULL

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Why noble gases exist as monoatomicgases and are chemically unreactive?


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Physical Properties of Group 18 Elements1. Group 18 elements have very small atom.

2. They are___________ gases a room temperature andpressure.

3. They have________ melting and boiling point.

4. They have__________ densities.

Table 1: Physical Properties of Group 1 Elements

4. From Table 1, when going down the group, atomic size anddensity_____________.

5. When going down the group, melting points and boiling points_______________

Uses of Group 18 elements

Helium Used to fill ____________ and ______________,

because the gas is very light. The divers oxygen tank contains a mixture of helium

(80%) and oxygen (20%).

Neon Advertising ____________.

Elements/

symbol

Electron

arrangement

Atomic

radius(nm)

Melting

points(C)

Boiling

points(C)

Density

(g cm-3

)

Helium 2 0.050 -270 -269 0.17

Neon 2.8 0.070 -248 -246 0.84

Radon 2.8.8 0.094 -189 -186 1.66

Krypton 2.8.18.8 0.109 -156 -152 3.45

Xenon 2.8.18.18.8 0.130 -112 -107 5.45

Radon 2.8.18.32.18.8 - -71 -62 -

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Television tubes. Airport ____________ bulb to help aero plane landing

safely.

Argon To fill light bulbs, it can last ________________ To provide inert atmosphere for _________ at high

temperature.

Krypton Used in ____________ to repair the retina of the eye. To fill _________________ flash lamps.

Radon Used in treatment of _________________.

Xenon Used in bubble chambers in atomic energy ___________.

PERIODIC TABLE OF ELEMENTSC. GROUP 1 ELEMENTS

7. The elements in Group 1 are

Lithium _______Sodium _______

___________ 2.8.8.1Rubidium ____________

_________ 2.8.18.18.8.1Francium ___________

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8. They are also known as_____________ which react withwater to form alkaline solutions.

9. All Group 1 elements have________ valence electron in their

outermost occupied shells.

Physical Properties of Group 1 Elements1. Group 1 elements are soft metals with______ densities and

____ melting points as compared to other metals such as ironand copper.

2. They have silvery and shiny__________.

3. They are _________ conductor of heat and electricity.

Table 1: Physical Properties of Group 1 Elements

6. From Table 1, when going down the group, atomic size anddensity____________.

7. When going down the group, melting points and boiling points_____________

Chemical Properties of Group 1 Elements

Elements/symbol

Electronarrangement

Atomicradius(nm)

Meltingpoints(C)

Boilingpoints(C)

Density(g cm-3)

Lithium, Li 2.1 0.15 180 1336 0.57

Sodium, Na 2.8.1 0.19 98 883 0.97Potassium, K 2.8.8.1 0.23 64 756 0.86

Rubidium, Rb 2.8.18.8.1 0.25 39 701 1.53

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Lithium, sodium and potassium have similar ____________________________ but differ in ________________.

1. Alkali metals react vigorously with water to produce alkaline_______________ solutions and_____________ gas.

Chemical equation;

2Li + 2H2O 2LiOH + H2Lithium Water Lithium Hydrogen

hydroxide gas

_______________________________________Sodium Water Sodium Hydrogen

hydroxide gas

________________________________________

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Potassium Water Potassium Hydrogenhydroxide gas

2. Alkali metals react rapidly with oxygen gas, to produce whitesolid _____________________

Chemical equations;

4Li + O2 2Li2OLithium Oxygen Lithium

gas oxide

____________________________Sodium Oxygen Sodium

gas oxide

______________________________Potassium Oxygen Potassium

gas oxide

3. Alkali metals burn in chlorine gas to form white solid________ _________________

Chemical reaction;

2Li + Cl2 2LiClLithium Chlorine Lithium

gas chloride

_____________________________Sodium Chlorine Sodium

gas chloride

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____________________________Potassium Chlorine Lithium

gas chloride

4. Alkali metals burn in bromine gas to form_______________.

For example,

2Li + Br2 2LiBrLithium Bromine Lithium

gas bromide

____________________________Sodium Bromine Sodium

gas bromide

______________________________Potassium Bromine Potassium

gas bromide

5. Therefore, alkali metals have similar chemical properties.

Alkali metals have______________________in their

outermost occupied shells.

Each of them reacts by donating ______________from its________________to form an ion with a charge of_____,thus achieving the___________electron arrangement of theatom of noble gas.

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Whyalkali metals have similarchemical properties?


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Li Li+ + 1e-

2.1 2

_________________________2.8.1 2.8

K K+ + 1e-_________________________

6. The reactivity of Group 1 elements_____________ down thegroup.

Going down Group 1, the atomic size (atomic radius)_______________.

The single valence electron in the outermost occupied shellbecomes____________ away from the nucleus

Hence, the attraction between the nucleus and the valenceelectron becomes_____________

Therefore, it is easier for the atom to_____________ thesingle valence

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WhyThe reactivity of Group 1

elements increases down the group?


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electron to achieve the stable electron arrangement.

Safety precautions in handling Group 1 elementsAlkali metals are very reactive. Safety precautions must be taken whenhandling alkali metals.

The elements must be stored in _______________ in bottles Do not hold alkali metals with your bare hands Use __________________ to handle them Wear safety goggles Wear safety gloves Use a small piece of alkali metal when conducting experiments


D. GROUP 17 ELEMENTS

1. The group 17 elements are:

Flourine 2.7

Chlorine __________

___________ 2.8.18.7

Iodine _________

________ 2.8.18.32.18.7

2. Group 17 elements are known as____________

3. Halogens exist as _____________ molecules.

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4. Halogens have__________ valence electrons.

Physical Properties of Group 17 Elements

1. All Group 17 elements are________________.

Element SymbolProton

Number

Physicalstate atroom

temperature

ColourMeltingpoint

Boilingpoint

Flourine 9 Gas

_______

_______Chlorine 17 Gas

Bromine 35 Liquid

Iodine 53 Solid

2. Halogen have_____ melting and boiling points becausetheir molecules are attracted to each other by_______forces.______ energy is needed to ________ the forces .

3. When going down the group, the melting and boilingpoints ___________. This is because the molecular size

__________.

Diagram:

Cl2

Cl2

Cl2

Cl2

van derWaalsforces

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1. Group 17 elements react with water, metal and alkali.

a) Halogen react with waterto form 2 acids

In general:

X2 + H2O HX + HOX ; X is halogen

HX and HOX solutions are__________. HOX solution exhibits_______________properties.

Example:

Cl2 + H2O HCl + HOCl

Chlorine Water Hydrochloric Hypochlorus

acid acid

___________________________________________________

Bromine Water Hydrobromic Hypobromus

acid acid

I2 + H2O HI + HOI

_____________________________________________________

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What is physicalstate of astatine?

Practical book Carry out anexperiment 4.2 page 39

HW: Draw diagram and answerthe question


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b) Halogens in gaseous state react with hot iron

To form a brown solid , iron(III) halides.

In general:

2Fe + 3X2 2FeX3 ; X is halogen

Example :

2Fe + ______ ________

Iron Bromine Iron(III) bromide

_____________________________________________

Iron Chlorine Iron(III) chloride

_____________________________________________

Iron Iodine Iron(III) iodide

c) Halogens react with sodium hydroxide solution , NaOH.

To form sodium halide, sodium halate and water

The halogens are_____________ during these reaction.

In general:

X2 + NaOH NaX + NaOX + H2O

[X is halogen]

Example:

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2 NaOH + I2 NaI + NaOI + H2O


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Fluorine is the most___________ element

Elelctronegativity of an element refers to the measurement of the___________ of an atom in its molecule to ________ electronstowards its _____________.

WHY they have similar chemical properties???

Halogens have_________valence electrons.

When halogens take part in chemical reactions, their atomalways gain one electron to achieve a_____________electron arrangement.

The explanation

a) The___________ size __________ down the group.

b) The distance of the outermost shell becomes

___________ from the____________.

c) The force of attraction of the nucleus on the electronsof the outermost shell__________.

d) The tendency of an atom to receive_________electron to

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Chlorine, Bromine and Iodine have_______

chemical properties but _______ in reactivity.

The Reactivity of Halogens__________ down the

rou .


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achieve an octet electron arrangement______________

Safety Precautions in handling Group 17 elements

1. The vapour of Flourine, Chlorine and Bromine are________________.

2. The following precaution should be taken when handlinghalogen:

a) Halogen gas and liquid should be handled inside a_______________

b) Wear safety________when handling halogen fumes.

c) Wear safety______when handling halogen materials.

Do It Yourself

Element X Y Z

Proton number 9 17 35

1. Elements X, Y and Z are same group in the periodictable.

a. What is the valence electron of the elements X,Y andZ? _________

b. Which group in the periodic table can you find theelements X,Y and Z? _________

c. Element Y can react with water. What are theproperties of the solution produced?

_____________________________

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d. Write an equation for the reaction between element Zand hot iron. ________________

3. List all halogen elements from the top to the bottom ofgroup 17. __________________________

4. Which are the most reactive and least reactivehalogen? ____________________________---

4. Write the chemical equations for the following reaction:a) Chlorine with water __________________________

b) bromine with iron ___________________________

c) iodine with sodium hydroxide

_____________________________________

5. Explain the changes to the reactivity of halogens when

going down group 17.

___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


E. Elements in a PERIOD 3

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Elements in period 3

Na Mg Al Si P S Cl Ar

2.8.1 2.8.2 2.8.3 2.8.4 2.8.5 2.8.6 2.8.7 2.8.8

Physical properties

symbol Na Mg Al Si P S Cl Ar

Proton number 11 12 13 14 15 16 17 18

Atomic radius (pm) 186 160 143 118 110 104 100 94

electronegativity 0.9 1.2 1.5 1.8 2.1 2.5 3.0 -

Melting point (oC) 98 650 660 1411 44 115 -101 -189

Boiling point (oC) 892 1105 2517 3231 280 444 -34 -186

Metal properties- element in period 3 can be classified into three type

metal : _____________semi-metal : ______________non-metal : __________________-

- the metal oxides are usually basic

- non-metallic oxides are acidic oxide

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The________________________changes from basic to amphoteric

and then acidic across the eriod.

__________________________________

__________________________________


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- Aluminium oxide, Al2O3 is an_____________

i. Aluminium oxide is a bases/alkaly when reacted with acid.

ii. Aluminium oxide is an acid when react with alkali.

Proton number

Size of atom

why?- All the element in period 3 have three filled electron shell but

the proton is increasing by one unit across the period- As a result, the increase of proton number is increasing the

electrostatic force between the nucleus and the valenceelectron

- The valence electron are pulled closer to the nucleus,

causing the atomic radius to decrease

Electronegativity

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Amphoteric oxides is_______that had_____and____properties

Al2O3 (p) + 6HCl (ak) ___________________________

Al2O3 (p) + 2NaOH (ak) + 3H2O (ce) 2NaAl(OH)4 (ak)

Proton number is increasing at one unit when across the period

The atomic radius is decreasing when across the period

The electronegativity increases across the period


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why?- Electronegativity is a measurement of the tendency of an

element to attract the electrons- The force of attraction of the nucleus is increase when

across the period because the size of atomic radius isdecreasing and the proton number is increasing.

Uses of semi-metals- Silicon is a semi-metal, known as metalloid.- Silicon is use in microelectronic industry like transistor,diode

and another electronic component.- Silicon can be built onto a crystal of silicon to make a

microchip.


E. Transitions Elements

Transitions elements are elements from group 3 to Group 12.

Character:- solid with shiny surfaces- ductile- malleable- high tensile strength- high melting and boiling points- high densities- good conductors of heat and electricity

(typical character of metals)

How to differentiate transition metal from other metal?

Three special characteristic for transition elements

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1. Transition elements show different oxidation number intheir compounds.

2. Transition elements form coloured ions or compounds.3. Transition elements and their compounds are useful

catalyst.1. Transition elements show different oxidation number in their

compounds.

They exhibit a wide range ofoxidation states or positively chargedforms. The positive oxidation states allow transition elements toform many different ionic and partially ionic compounds.

All the transition elements except scandium and zinc havemore than one oxidation number.

For example iron. Iron have 2 oxidation number as iniron(II), Fe2+ and iron(III), Fe3+

Example:

Compound Formula Oxidation number

Iron(II) sulphate FeSO4Iron(III) chloride FeCl3Copper(I) oxide Cu2O

Copper(II) sulphate CuSO4Manganese(II) sulphate MnSO4Manganese(IV) oxide MnO2

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http://chemistry.about.com/library/weekly/aa122002a.htmhttp://chemistry.about.com/library/weekly/aa122002a.htm


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2. Transition elements form coloured ions or compounds

Gemstones

Transition metals solutions

Ruby Emerald Sapphire Amethyst

cobalt(II) nitrate

(red)

potassium dichromate(orange)

potassium chromate(yellow)

nickel(II) chloride

(light blue)

copper(II) sulfate(blue)

potassium permanganate(purple)

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Do you know why the gemstones

have different colour?


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http://chemistry.about.com

3. Transition elements and their compounds are useful catalyst

Catalyst: Chemical substance use to speed up the chemicalreactions

A specific catalyst is used for a specific reaction.

Example

Process Catalyst To produce

Haber Process

Contact ProcessOstwald Process

Hydrogenation

Transitions elements are widely used in our daily lives.

Chapter 4 : Periodic Table of Elements

Exercise :

1. Below is a list of elements represented by the symbols as shown:

P11 , Q

12

6 , R19

9 , S27

13 , T35

17 , U39

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(a) Pick a pair of elements that belongs to the same Group in the Periodic Table.Explain your answer.

[2 m

(b) State the

Group in which element Q belongs to.

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[Period in which element Q belongs to.

[

(c) State elements which are

(i) metals :

(ii) non-metals :

[2

(d) Which element will form amphoteric oxide?

Which element reacts with cold water?

Write a balanced chemical equation for the reaction.

(f) Write the formula of the ion formed by element S.

Explain the meaning of the term electronegativity.

Which of the two elements R and T is more electronegative?

Explain your answer in (g)(ii).

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[2

Which of the two elements S and T has smaller atomic size?

Explain your answer in (h)(i).

[3

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2 Group 18 Elements Updated Student