chemistry- atomic bonding

states of matter

solid, liquid, gas

how does a solid get to a liquid

melting

how does a liquid become a gas

evaporating

how does a gas become a liquid

condensing

how does a liquid go to a solid

freezing

changes shape and volume according to its container

gas

changes neither shape or volume

solid

does not change volume but changes shape according to its container

liquid

has the strongest force of attraction

solid

has the weakest force of attraction

gas

how do atoms gain a positive charge

loose an electron

how do atoms gain a negative charge

gain an electron

formulas are to do with

how many atoms there are

positive and negative atoms attract to each other until

a better option comes along

Ions are

charged particles, they can be single (eg Cl-) or in groups (eg NO3-)

When atoms loose or gain electrons they become

ions

when atoms become ions they are trying to

get a full outer shell

when metals form ions they

Lose electrons from their outer shell to form positive ions

When non metals form ions they

gain electrons into their outer shell to form negative ions

the number of electrons gained or lost is the same as

the charge

ionic bonding

when a metal and non metal react together

oppositely charged ions are strongly attracted to one another by

electrostatic forces

ionic compounds have a

Regular lattice structure

regular lattice structure is

ions are closely packed, strong electrostatic forces of attraction between oppositely charged ions

all Ionic compounds have

\

high melting/boiling points- due to the strong bonds between the ions

ionic compounds can not conduct electricity when solid

due to the ions being held in place

ionic compounds can conduct electricity when aqueous

due to the ions being free to move

some ionic compounds are soluble

ions separate are free to move

covalent bonding

sharing of electrons between two non-metal atoms

the positively charged nuculei of bonding atoms are attracted to the shared pair of electrons by

electrostatic forces

Atoms only share electrons in the

outer shell

covalent bonds happen in

compounds of non-metals and non-metal elements

Simple molecular substances are

Made up of molecules containing a few atoms joined together by covalent bonds

atoms within the molecules are held together by

strong covalent bonds

the force of attraction in simple covalent bonds are

very weak

melting/boiling point is

very low

to melt a simple molecule compound you have to

break the intermolecular forces

most molecular substances are ... at room temperature

gas or liquids

as molecules get bigger the

intermolecular forces get stronger

simple molecular compounds don't conduct electricity because

they are not charged and there are no free electrons

inside a polymer there is

lots of small units are linked together to form a long molecule that has repeating sections

All the atoms in a polymer are joined by

strong covalent bonds

most polymers are ... at room temperature

solid

the intermolecular forces are ... larger between polymers than simple covalent bonds

larger

in a giant covalent structure all atoms are

joined by strong covalent bonds

Giant covalent structures have

high melting and boiling points

if a structure dos not contain free electrons it can not

conduct electricity

Why does graphite leave a mark when rubbed on paper

layers of carbon atoms slide off due to weak intermolecular forces

How is graphite able to conduct electricity

delocalised electrons move around/flow creating a electric current

What makes graphite a good lubricant

because is soft and slippery layers can slide

Why do diamond and graphite have such high melting points

lots of strong covalent bonds lots of energy needed to melt them

Why are diamonds so hard

4 strong covalent bonds between each atom

How many bonds hold the carbon atoms together in graphite

3 carbon atoms

What holds the layers of graphite together

weak intermolecular forces

In graphite, what are the spare electrons on each carbon atom able to do

delocalised electrons can move

How are the atoms in covalent substances held together

sharing electrons

Which element is both graphite and diamond made of

carbon

What type of structure do both diamond and graphite form

giant covalent structure

How many bonds hold the carbon atoms together in diamond

4 carbon atoms

Graphite is used for

pencils, Dry Lubricants

Graphite is a GOOD

electrical conductor

Graphite is very

soft

What is an electrical current

the flow of electrons

The melting points of diamond and graphite are

high

Diamond and graphite are

non-metallic

Diamond is a POOR

electrical conductor

Diamond is used for

drill tips, saws and jewellery

Why are metals hard

because the layer which the metals structure is made of can slide over to each other without breaking

Why are metals very good conductors

because of the delocalised electrons in the metal, the delocalised electrons carry electrical charge through the metal and they are good thermal conductors because they carry energy through the metal

fullerine

A form of carbon that consists of atoms arrange in the shape of a hollow sphere.

fullerine are arranged in

hexagons

fullerines are used to

cage other molecules, deliver a drug into the body

Buckminsterfullerene

the first fullerene discovered formuler C60

Fullerenes have a huge

surface area

Fullerenes make great

lubricants

electrons in the outer shell of a metal are

delocalised

in metallic bonding there are strong forces of

electrostatic forces

in metallic bonding there are strong forces of electrostatic forces between

positive ions and the shared negative electrons

the forces of attraction

hold the atoms together in a regular structure

metallic bonding is very

strong

substances that are held together by metallic bonding include

metallic elements and alloys

most compounds that have metallic bonding have

high melting/boiling point and solid at room temperature

Metals are good conductors of heat and electricity

the delocalised electrons carry electric charge and thermal heat throughout the structure

Metals are malleable

The layers can be can be hammered into sheets or slide over each other

Pure metals are no right for certain jobs because

they can be to soft

pure metals are mixed with other metals to make them ...

harder

Alloy metals

mix of 2 or more metals or a metal and another element

alloys are

harder and more useful than pure metals

when a pure metal becomes mixed with a element it will

distort the layers of atoms making them harder to slide off each other