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Chemistry Additional (C2) Calculating RAM The RAM is the Relative Atomic Mass. The RAM is shown on the periodic table. What is an isotope? Isotopes are atoms of an element that have the same number of Protons and Electrons but have different numbers of Neutrons. They have the same atomic number but have a different atomic mass.

Chemistry Additional Notes Edexcel

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Text of Chemistry Additional Notes Edexcel

Chemistry Additional (C2)Calculating RAMThe RAM is the Relative Atomic Mass. The RAM is shown on the periodic table.

What is an isotope?Isotopes are atoms of an element that have the same number of Protons and Electrons but have different numbers of Neutrons. They have the same atomic number but have a different atomic mass.

What is an Ionic Bond?

The electron is Transferred How is an ion formed?Ions (electrically charged particles) are formed when an atoms loose or gain electrons. Metal atoms form positive ions, and non-metal atoms form negative ions.-ide, -ite and ate2-

SulfideIts a Mono-tomic ion (by itself)S

Contains Sulfur

2- SO

Sulfite3Contains oxygen

Contains Sulfur 42- SO

SulfateContains Sulfur

Ionic Compounds Properties High melting points Conducts electricity when molten or dissolved in water

PrecipitationTransition metal hydroxides are insoluble in water.If a solution of any soluble transition metal compound is mixed with sodium hydroxide solution then we get a displacement reaction. The sodium is the more reactive metal, and displaces the transition metal from its compound. The transition metal hydroxide is produced as a result. As this is insoluble in water it appears as a solid in the liquid. A solid produced in a liquid in this way is called a precipitate.Soluble and Insoluble Salts

Soluble salts form clear solutions. Insoluble salts form cloudy solutions.How to remember:SPANSodiumPotassiumSolubleAmmoniumNitrateInsolubleChlorides and sulphates are also soluble except for:Silver ChlorideLead ChlorideLead SulfateCalcium SulfateBarium SulfateCarbonates and Hydroxides are insoluble except for:Sodium CarbonatePotassium CarbonateAmmonium CarbonateBarium MealPatients often are required to have a barium meal before an x-ray as it reflects the x-rays and allows the doctor to see a picture of the gut. Barium is toxic but it is insoluble and therefore cannot get into the blood stream.Flame Test Colours

Yellow Lilac Red/Orange Blue/Green

Tests for Carbonates, Sulphates and ChloridesCarbonates () = Carbon dioxide is present if the gas turns the lime water milky.Sulfates () = Add dilute HCL and barium Chloride solution. A white precipitate of Barium Sulfate will form if it was a Sulfate. Chloride (Cl-) = Add dilute nitric acid and silver nitrate solution. If a white precipitate of silver chloride is present, chlorine ions are present.SpectroscopyThe patterns of light emitted from a headed sample are studied. Each element has a unique pattern. This helps scientists to identify an element quickly and efficiently and can also help them to discover new elements. Rubidium and caesium were discovered using this method.

Covalent Bond

The electron is SharedWhat is a moleculeA group of atoms bonded together.Ionic and Covalent Substances

Simple Molecular Substances and Giant Covalent StructuresProperties of simple molecular substancesLow melting and boiling points- This is because the weak intermolecular forces break down easily.Non-conductive- Substances with a simple molecular structure do not conductelectricity. This is because they do not have any free electrons or an overall electric charge.Properties of giant covalent structuresVery high melting points- Substances with giant covalent structures have very high melting points, because a lot of strong covalent bonds must be broken. Graphite, for example, has a melting point of more than 3,600C.Variable conductivity- Diamond does not conduct electricity. Graphite contains free electrons, so it does conduct electricity. Silicon is semi-conductive - that is, midway between non-conductive and conductive.

Graphite and Carbon PropertiesGraphiteGraphite is a form of carbon in which the carbon atoms form layers. These layers can slide over each other, so graphite is much softer than diamond. It is used in pencils, and as a lubricant. Each carbon atom in a layer is joined to only three other carbon atoms. Graphite conducts electricity.DiamondDiamond is a form of carbon in which each carbon atom is joined to four other carbon atoms, forming a giant covalent structure. As a result, diamond is very hard and has a high melting point. It does not conduct electricity.

Miscible and immiscible liquids.Miscible liquids can mix completely. Immiscible liquids cannot. To separate immiscible liquids, you could use a separation funnel. To use it, you open the valve and let the first liquid run out. Then close the valve, replace the beaker and open it again. The second liquid will then run into the second beaker.

Fractional distillationFractional distillation can be used to separate miscible liquids. This is due to the different boiling points of each liquids. The liquid with the lowest boiling points will separate first. Then the next liquid will boil after that.Fractional distillation of air-Air is made up of:

To separate these: Air is filtered to remove dust The air is then cooled to -200c Water condenses first Carbon dioxide then freezes The remaining mixtures go into a fractional distillation column. The nitrogen and oxygen are then heated. Due to the different heats at either end of the column and their different boiling points they both separate at different ends of the column. Nitrogen will leave at the cold end and oxygen will leave at the warm end

Paper ChromatographyColours are put on a pencil line on a piece of paper. The paper is then stood in solvent, ensuring the solvent is below the line. Then the colours will separate out. If the colours are at the same height. Then they contain the same colours.

Structure of metalsThe atoms in a metal are regularly arranged and are held together with metallic bonds. These metallic bonds means that the metal has a giant structure consisting of positive ions and free electrons. This is because the metallic bond allows the outer electrons to become delocalised (Move freely). This creates a sea of delocalised electrons. This means they are good conductors as electrons can move freely through the metal. This giant structure means there is a strong metallic bond which means it has a high melting point. This also means it is insoluble.The regularly arranged structure means layers can easily slide over each other.

Alkali MetalsAlkali metals are shown in group one in the periodic table. Alkali metals soft and have low melting points. Each of the alkali metals react to form hydroxides in water as shown on the right.

HalogensHalogens are found in group 7 of the periodic table. They all have 7 electrons in their outer shell. Their properties are as follows:

Halogens can react with metals to form metal halides. They can also react with hydrogen to form hydrogen halides. Hydrogen halides are soluble and can be dissolved into water to form acidic solutions. For example hydrogen chloride can be dissolved in water to form HCL hydrochloric acid. Most ReactiveLeast Reactive

The higer up group 7 the element is, the more reactive it is. If a more reactive halogen reacts with a solution containing a halide. That halogen will be displaed.

Noble GasesNoble gases are found in group 0 of the periodic table. They are colourless at room temperature. They are also inert which means they are very unreactive. This is because they have a full outer shell and therefore do not need to give or take any electrons. They are also non-flammable. Argon is used in filament lamps. This is because it is non-flammable and helps the filament to not burn out as quick. Helium can be used in party balloons this is because it has a low density which allows it float.Endothermic and Exothermic Reactions

Rates of reactionWhat effects the rate of reaction?

Catalytic converterIn a catalytic converter, harmful gases react with oxygen.A clean gas is then let out. This is often used in cars.

Rates of reaction graphs