Chemistry - Structure and Bonding + periodic table

Describe Antoine Lavoisier’s periodic table (1789)

Split all ‘elements’ into 4 categories: acid making, gas-like, metallic, and earthy. These included light, heat, and lime (calcium oxide)

What had not yet been discovered when early scientists tried to create the periodic table

Protons, electron, neutrons

Describe John Newlands periodic table (1864)

He organised the elements in rows of 8 (Law of Octaves), stating that elements in a column all had similar properties. Many of the elements were in the same space as others, and, as some had not yet been discovered, a lot of them that were put in the same group did not actually share properties

Disadvantages of Newland’s table

Two elements may share a space (eg. Cobalt and Nickel)
Some elements in the same group had very different properties
No clear division between metals and non - metals
Newland didn’t allow spaces for new elements

How did Mendeleev’s table improve on Lavoisier’s and Newland’s

Included elements which had not yet been discovered
Organised elements in order of their atomic mass - but with some exceptions to ensure that they matched the properties of their group
Separates Metals and Non metals

Why did scientists not accept Mendleev’s table immediately

Did not see evidence for his predictions of eka- aluminium
Left gaps = table is incomplete
Some elements not in order of RAM means that the rule is not universal

Why did the discovery of Galium convince other scientists that Mendeleev was correct

His prediction was very accurate - especially of its atomic mass. It perfectly filled the gap in group 3

The discovery of what explained why the rule of RAM could not always be followed

Isotopes

Where are the alkaline metals

Group one

Metals are elements that react to form ions

positive

What to the alkaline metals form when they reacts with water

An alkali (shock)

What is more reactive: Lithium or Francium

Francium

Why is Francium more reactive than Lithium

It has more outer shells ->outer most shell is further away from nucleus -> forces of attraction holding it in place are weaker -> can react more easily with other elements bc it needs to lose it’s electron

What can be observed when lithium reacts with oxygen

Burns with a red flame, giving a white solid

What can be observed when lithium reacts with water

Sizzling, steam, vibrating, moving side to side across the surface of the water, gas produced. Water turns purple with a universal indicator

What can be observed when lithium reacts with chlorine

Vigorous reaction, white solid formed which dissolves in water to give a neutral solution

What can be observed when sodium reacts with oxygen

Burns with a golden yellow colour to give a white solid

What can be observed when sodium reacts with water

Fizzing, burning, cracking, bright orange flame, violent reaction. Water turns purple with a universal indicator

What can be observed when sodium reacts with chlorine

Burns intense yellow/orange colour. White smoke produced. Exothermic reaction. Neutral solution formed

What can be observed when potassium reacts with oxygen

Burns with a lilac flame to give a white solid

What can be observed when potassium reacts with water

Fizzing (effervesance), crackling, lilac flame produced. Water turns purple with a universal indicator

What can be observed when potassium reacts with chlorine

Large bright lilac flame, suddenly pops and spontaneously combusts, potassium deposits can be seen

Why is it unsafe to use rubidium, caesium, and francium in a reaction in a lab

It reacts violently with water, and oxygen, so causes a large explosion

What is formed when an alkali metal reacts with water

Metal hydroxide and hydrogen

What is formed when an alkali metal reacts with oxygen

Metal oxide

What is formed when an alkali metal reacts with chlorine

Metal chloride

Where are the halogens

Group 7

What do the halogens form when they react with water

A salt

What is more reactive, tennessine or fluorine

fluorine

Why is fluorine more reactive than than tennessine

The halogens need to gain an electron -> fluorine’s outer shell is closer to its nucleus, so is under greater attractive force -> this means that its forces of attraction will be able to act more strongly on another atom’s electron, as there is a shorter distance -> it reacts and gains an electron more easily

Describe fluorine

Poisonous yellow gas. Very reactive

Describe chlorine

Poisonous green gas. Reactive, but less than fluorine

Describe bromine

Red/brown poisonous volatile liquid

Describe iodine

Grey solid, can form poisonous purple vapours, but is also an antiseptic

Halogens always come in____

Diatomic molecules, bonded covalently (pairs)

What do halogens form with non metals

Covalent bonds

What do halogens form with metals

Ionic bonds

When you go down the halogens, the melting and boiling point increases/decreases

increases

When you go down the halogens, the reactivity increases/decreases

decreases

What is a halogen called when it forms an ionic compound

Halide

What is a displacement reaction

A reaction in which a more reactive element displaces another one in a compound

If chlorine is added to potassium bromide, what happens/what is formed

Potassium chloride + bromine

If iodine is added to potassium fluoride, what happens/what is formed

No change

What colour are halide salts

colourless

What colour is bromine water

orange/yellow

What colour is chlorine water

colourless

What colour is iodine water

brown

When you mix (insert halogen) water with a salt, what happens

Colour change

What do you observe when you mix potassium bromide with chlorine in water and why do you observe this

Solution trunks from colourless to orange/yellow.
Before, chlorine was present (which is colourless), but the chlorine displaces the bromine, and the bromine is orange/yellow

What colour is chlorine when dissolved in hexane

Pale green

What colour is bromine when dissolved in hexane

orange

What colour is iodine when dissolved in hexane

purple

What are group 0/group 8 elements called

Noble gases

True or False: Noble gases are very reactive?

False - Noble gases are unreactive

Why are noble gases unreactive?

They have a full outer shell of electrons, so don’t need to gain or lose any to be stable. This means that they don’t react with other elements

Does the melting and boiling point elements increase or decrease as you move down the group and why

Increase because, as you move down the group, the atoms have more electrons. This means that the intermolecular forces of attraction between molecules are stronger and less easily overcome, so it takes more energy to break them.

Alkali metal or transition metal: low melting points

Alkali metals

Alkali metal or transition metal: high melting point

Transition metals

Alkali metal or transition metal: not very reactive

Transition metals

Alkali metal or transition metal: very reactive

Alkali metals

Alkali metal or transition metal: can be used as a catalyst

Transition metals

Alkali metal or transition metal: coloured compounds

Transition metals

Alkali metal or transition metal: white compounds

Alkali metals

Alkali metal or transition metal: ionic compounds formed when reacted with non metals

Alkali metals + Transition metals

Alkali metal or transition metal: good thermal and electrical conductors

Transition metals + alkali metals

Alkali metal or transition metal: strong and hard

Transition metals

Alkali metal or transition metal: soft and can be cut with a knife

Alkali metals

Alkali metal or transition metal: high density

Transition metals

Alkali metal or transition metal: low density, some float on water

Alkali metals

Alkali metal or transition metal: form an alkali solution with water

Alkali metals

Alkali metal or transition metal: react with water releasing a hydrogen gas

Alkali metals

Alkali metal or transition metal: form 1+ ions

Alkali metals

Alkali metal or transition metal: can form different ions

Transition metals

Describe transition metals (compounds and ions, uses, density, melting point)

Coloured compounds, different ions formed, used as catalysts, jewellery etc, high density, high melting point

Solid to liquid

melting

Liquid to gas

evaporation

Gas to liquid

condensation

Liquid to solid

solidifying/feezing

Solid to gas

deposition

Gas to solid

sublimation

What does a graph showing ice/water/steam being heated look like (image on other side)

What is happening at A

Ice is being heated, and the particles are vibrating faster

What is happening at B

Melting

What is happening at C

Water is being heated, and the particles are moving and vibrating more vigorously

What is happening at D

Evaporation

What is happening at E

Steam is being heated, and as it has more kinetic energy, is moving faster, making the particles spread out, and the volume increase

What is the structure of a diamond

Giant lattice. Made up of carbon atoms, which each bond to 4 other carbons

Why do diamonds have a high melting point

Giant lattice structure - each c bonds to 4 others
Covalent bonds between them are strong
Lots of energy is needed to break these bonds

Why are diamonds very strong

Giant lattice structure - each c bonds to 4 others
Covalent bonds between them are strong
It is very difficult to move any carbon atom out of place

Why do diamonds no conduct electricity

Giant lattice structure - each c bonds to 4 others
No electrons are free to carry charge
Diamonds cannot conduct electricity

What are the uses of diamonds

Gemstones
Abrasures
Rock drills and saws
Cut glass

What is the structure of sand

Giant Lattice. Made up of silicon (which bonds to 4 atoms) and oxygen (which bonds to 2). Looks similar to diamond except there is an oxygen atom between each silicon bond

True or false: the properties of sand are very similar to the properties of a diamond

True!

True or false - sand cannot contain impurities

False - it can contain many impurities like calcium carbonate

What is the structure of graphite

Hexagonal rings bonded together by covalent bonds. Each Carbon atom is bonded to 3 others. The layers are attracted to each other by intermolecular forces

Why is graphite soft and slippery

Intermolecular forces between layers are weak
Layers easily move and slide over each other

Why can graphite conduct electricity

Each carbon atom only bonds to three others
There is a delocalised electron per carbon atom
These can carry heat and electricity
Graphite can conduct electricity

What is the name for one layer of graphite

Graphene

Uses of graphite

Pencils
Absorbs neutrons in nuclear reactions

Structure of fullerenes

Connecting hexagonal rings. However, some rings may have 5 or 7 carbon atoms. They can form a cage like/ball structure, or a tube