Applied science Task 1 [Abcdefghijk]

7/23/2019 Applied science Task 1 [Abcdefghijk]

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Task 1

Task 1A-

Atomic structure - This is just the structure of an atom, it generally consists of anucleus which contains protons and neutrons, surrounded by negatively chargedelectrons revolving in orbits at varying distances from the nucleus.

Electronic structure con!guration" - This is the way electrons are arranged around

the nuclei of atoms in various orbitals. The electrons in an atom occupy energy

levels. These are also called shells, each electron in an atom is found in a particular

energy level.

#ydrogen

#elium

$ithium

%eryllium


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%oron

&arbon

'itrogen

()ygen

*luorine

'eon


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Aluminum

&alcium


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The periodic table consists of elements that are in groups which increase in atomic

numbers the further you go across. A group is a vertical column of elements, they

were traditionally numbered +-++ plus ero for the noble gases the elements in the

same group form a chemical family which have similar properties. /hen theelements go down a group the atomic radius would increase, this is because there

are more shells being added so more shielding is occurring between the outer shell

and the nucleus.

Atoms with the same number of protons but di0erent number of neutrons are called

isotopes. i0erent isotopes of the same element react chemically in the e)actly the

same way. Atoms of di0erent isotopes of the same element vary in mass number

because of the di0erent number of neutrons in their nuclei.

This is an e)ample of a #ydrogen isotope since there are more neutrons in the

nucleus.


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This is an e)ample of a $ithium isotope since there is an e)tra neutron in one of the

atoms.

Task 1% 2

+onic bonding is where positive and negative ions attract one another and bind

together forming a new substance.

3odium chloride consists of 'a4 ions and &l- ions bonded together.

5agnesium o)ide consists of 5g64 and (64 ions bonded together.


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Task 1& -

A covalent bond is formed between non-metal atoms, which combine together by

sharing electrons. &ovalent compounds have no free electrons and ions so they

don7t conduct electricity.

E)amples of covalent compounds are methane and ammonia

5ethane


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Ammonia

Task 1 - 3tate what is meant by a dative &ovalent bond, give one e)ample of a

compound that uses a dative covalent bond, include dot cross diagrams and shell

diagrams.

A dative covalent bond is a covalent bond a shared pair of electrons" in which bothelectrons come from the same atom.

In the reaction between ammonia and hydrogen chloride, if the colourless gases are allowed to mix, a

thick white smoke of solid ammonium chloride is formed.

Ammonium ions, '#84, are formed by the transfer of a hydrogen ion from the

hydrogen chloride to the lone pair of electrons on the ammonia molecule.


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/hen the ammonium ion, '#84, is formed, the fourth hydrogen is attached by a

dative covalent bond, because only the hydrogen9s nucleus is transferred from the

chlorine to the nitrogen. The hydrogen9s electron is left behind on the chlorine to

form a negative chloride ion.

(nce the ammonium ion has been formed it is impossible to tell any di0erencebetween the dative covalent and the ordinary covalent bonds. Although the

electrons are shown di0erently in the diagram, there is no di0erence between them

in reality.

Task 1E - 3tate how carbon is bonded in graphite, include a diagram showing how

the atoms are arranged.

:raphite is a allotrope of carbon in which the carbon atoms form layers. +t7s

properties are similar to diamond where it is lustrus, has a high melting point and is

insoluble in water. :raphite has a giant molecular structure due to its e)tremely

strong and abundance of covalent bonds. Each carbon atom is covalently bonded to

three other carbon atoms, compared to four in diamond. The layers of carbon slide

over each other easily as there are weak forces between them, making graphite

slippery, graphite contains free delocalised" electrons, which can move through the

graphite, carrying charge from place to place and allowing graphite to conduct

electricity.


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Task 1* - 3tate how carbon is bonded in diamond, include a diagram showing how

the atoms are arranged.

iamond is another allotrope of carbon it is lustrous, colourless, hard, and insoluble

in water, does not conduct water and has a high melting point. iamond9s hardnessand high melting point make it useful for cutting tools, such as the diamond-tipped

discs used to cut bricks and concrete. iamond has a giant molecular structure.

Each carbon atom is covalently bonded to four other carbon atoms. A lot of energy

is needed to separate the atoms in diamond. This is because covalent bonds are

strong, and diamond contains very many covalent bonds. This makes diamond9s

melting point and boiling point very high.

Task 1: -3tate how bonding occurs in metals, include a diagram showing how the

atoms are arranged.


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The particles in a metal are held together by metallic bonds. 5etallic bonding is the

strong attraction between closely packed positive metal ions and a sea of

delocalised electrons. The attraction between the metal ions and the delocalised

electrons must be overcome to melt or to boil a metal. 3ome of the attractions mustbe overcome to melt a metal and all of them must be overcome to boil it. These

attractive forces are strong, so metals have high melting and boiling points. The

delocalised electrons are able to move through the metal structure. /hen a

potential di0erence is applied, they will move together, allowing an electric current

to ;ow through the metal.

Task 1# - escribe %ohr7s theory to describe electronic structure, including

diagrams. +n order to do this successfully you will need to refer to - ?esearch the periodic table, write a paragraph to describe the structure of

the periodic table and how the elements are arranged you will need to include the

following key words

Applied science Task 1 [Abcdefghijk]

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