Year 10 Revision booklet Chemistry Easter holidays Revision Instructions: Use the knowledge organizer to help you answer the questions on the revision sheets. Atomic Structure

Atoms are the basic building Periods in the periodic table. In each (horizontal blocks of ordinary matter. row), the atomic numbers increase from left to right. Atoms can join together to The periods are numbered 1 through 7 on the left-hand form molecules, which in side of the table. Elements that are in the same period turn form most of the objects have chemical properties that are not all that similar. around you. Atoms are composed of particles called protons, electrons and neutrons.

Mixtures, Elements & Compounds Discovery of the nucleus An element is a substance made from only one type of atom. For example. is made In 1909 Ernest Rutherford designed an experiment to test the plum entirely from carbon atoms. pudding model. In the experiment, positively charged alpha particles were fired at thin foil. Most alpha particles went straight through the foil. But a few were scattered in different directions. 0 Elements A compound is a molecule made of atoms from This evidence led Rutherford to suggest a new model for the atom, called different elements. All compounds are the nuclear model. In the nuclear model: The group 0 elements, the noble gases, are all molecules, but not all molecules are • the mass of an atom is concentrated at its centre, the nucleus unreactive non- gases. They show trends in their compounds. gas (H2) is a molecule, • the nucleus is positively charged physical properties. Their uses depend on their but not a compound because it is made of only inertness, low density and non-flammability. one element. Atomic Structure Group 1 Elements A mixture contains two or more substances. Electrons in shells. Electrons in atoms that have not reacted chemically with each occupy energy levels, also called The Group 1 elements in the periodic table are known as the alkali other. A mixture is made of little bits of each electron shells, outside the nucleus . substance mixed together. A mixture can be . They include , and , which all react Different shells can hold different vigorously with water to produce an alkaline solution. separated by physical methods, a compound maximum numbers of electrons. The can not. electrons in an atom occupy the lowest Plumb Pudding Model available energy level first Group 7 Elements The Plum Pudding Model is a The Group 7 elements are called the . They are placed in the model of atomic structure Mendeleev vertical column, second from the right, in the periodic table . proposed by J.J. Thomson in the , and are the three common Group 7 late 19th century. Thomson had Mendeleev left gaps in his table for elements not known at the elements. Group 7 elements form salts when they react with metals. discovered that atoms are time. By looking at the properties of the elements next to a gap, composite objects, made of pieces he could also predict the properties of these undiscovered elements. For example, Mendeleev predicted the existence of with positive and negative charge, Properties of Metals and that the negatively charged 'eka-', which would fit into a gap below silicon. Another electrons within the atom were scientist later discovered the missing element, . Its very small compared to the entire properties were found to be similar to the predicted ones and atom. confirmed Mendeleev's periodic table. Atomic Theory

Niels Bohr adapted Ernest Rutherford's nuclear model. Bohr did calculations that led him to suggest that electrons orbit the nucleus in shells. The shells are at certain distances from the nucleus. Further experiments led to the idea that the nucleus contained small particles, called protons. James Chadwick found evidence for the existence of particles in the nucleus with mass but no charge. These particles are called neutrons. This led to another development of the atomic model, which is still used today. Write the word equation for: Explain crystallisation as a separation Burning in air technique C1 Atomic Structure and the Periodic Table Can you write the balanced symbol AQA Trilogy equation?

Define the following terms: Balance the symbol equations below: Draw a diagram to illustrate chromatography Atom as a separation technique

H2SO4 + NaOH  Na2SO4 + H2O Element

Zn + O  ZnO Number of protons = Compound 2 Number of neutrons =

Mixture CH4 + O2  CO2 + H2O Number of electrons =

Write the symbols for the following Simple distillation Explain simple distillation as a separation Describe the difference between the elements: technique, shown in the diagram plum pudding and the nuclear model of an atom Carbon Sodium Magnesium Chlorine

Write the name of the compound: fractional distillation Explain fractional distillation as a separation Where in an atom are the neutrons and technique CO2 proton? The number of protons = the number H2O of______Atomic number is the number of NaCl ______Mass number is the number of CuSO4 ______+ the number of ______Isotopes have a different number of ______In the periodic table, the elements are When developing the periodic table, Properties of metals arranged in order of their ______Why did Medeleev leave gaps? • number C1 Atomic Structure • Elements in the same group, have the and the Periodic Table same number of ______• AQA Trilogy Groups go ______• Approximately how may elements are in Periods go ______the periodic table? •

Draw the electron structure for sodium What is group 1 also known as? Delete as appropriate: Properties of non-metals • As you go down group 1, what If you remove electrons from an atom is happens to the reactivity? becomes positive/ negative •

If you add electrons to an atom it • How many electrons are in the becomes positive/negative outer shell of a group 1 metal? •

•

Draw the electron structure for chlorine What is group 7 also known as? What is an ? To work out the using the abundance of we can As you go down group 7, what use the following calculation: happens to the reactivity?

What happens to melting point and (% of isotope 1 × mass of isotope 1) boiling point as you go down the group? + (% of isotope 2 × mass of isotope 2) How many electrons are in the ÷ 100 outer shell of a group 7 element?

Draw the electron structure for chlorine What is group 0 also know as? Copper has two stable isotopes Cu-63 which In any sample of Chlorine 25% will has an abundance of 69.2% and Cu-65 which be 37Cl and 75% 35Cl. Calculate the In group 0, how many electrons has an abundance of 30.8% relative atomic mass to 1dp. are in the outer shell? Calculate relative atomic mass to 1dp.

How is boiling point affected as you go down the group? Ionic Bonding Diamond Graphite In diamond, each carbon atom Positive and negative ions form when a metal reacts with a In graphite, each carbon atom forms three forms four covalent bonds covalent bonds with three other carbon atoms, non-metal, by transferring electrons. The oppositely with other carbon atoms in a charged ions are strongly attracted to each other, forming forming layers of hexagonal rings which have giant covalent structure, so ionic no covalent bonds between the layers. In diamond is very hard, has a graphite, one electron from each carbon atom A dot and cross diagram models the transfer of electrons very high melting point and is delocalised. from metal atoms to non-metal atoms. The electrons from does not conduct electricity. one atom are shown as dots, and the electrons from the Diamond is a giant covalent Graphite is a giant covalent substance in other atom are shown as crosses. substance in which: which: Giant Ionic Compounds • each carbon atom is • each carbon atom is joined to three joined to four other other carbon atoms by covalent bonds carbon atoms by An ionic compound is a giant structure of ions. The ions have a • the carbon atoms form a hexagonal covalent bonds regular, repeating arrangement called an ionic lattice. The lattice is layered network structure • the carbon atoms form formed because the ions attract each other and form a regular • the layers have weak forces between a regular tetrahedral pattern with oppositely charged ions next to each other. them and can slide over each other network structure The ions in an ionic compound held together in a giant ionic lattice. • each carbon atom has one un-bonded • there are no free Ionic compounds have high melting points and boiling points. Ionic outer electron electrons compounds form crystals (which can be cleaved along certain • these un-bonded electrons are planes). Ionic compounds do not conduct electricity when solid. delocalised, and are free to move Fullerene Covalent Bonding Fullerenes are molecules of carbon atoms with hollow shapes. The structure of fullerenes is based on hexagonal rings of carbon atoms but they may also contain A covalent bond is formed when two atoms share a pair of rings with five or seven carbon atoms. The first fullerene to be discovered was electrons. Covalent bonding occurs in most non-metal Buckminsterfullerene (C60) which has a spherical shape. elements, and in compounds formed between non-metals These shared electrons are found in the outer shells of the atoms. Usually each atom contributes one electron to the Metallic Bonding shared pair of electrons. Metals consist of giant structures of atoms arranged in a regular pattern. The electrons from the outer shells of the metal atoms are delocalised, and are Simple Covalent Molecules free to move through the whole structure. This sharing of delocalised electrons results in strong metallic bonding. Hydrogen, ammonia, methane and water are also simple • they are electrical conductors because their delocalised electrons carry molecules with covalent bonds. All have very strong bonds electrical charge through the metal between the atoms, but much weaker forces holding the • they are good conductors of thermal energy because their delocalised molecules together. When one of these substances melts electrons transfer energy or boils, it is these weak 'intermolecular forces' that break, • they have high melting points and boiling points, because the metallic bonding not the strong covalent bonds. in the giant structure of a metal is very strong - large amounts of energy are needed to overcome the metallic bonds in melting and boiling

Giant Covalent Structures Alloys Properties of giant covalent structures In a pure metal, the force needed to make • Very high melting points - the layers slide over each other is small. Substances with giant This explains why many pure metals are covalent structures have soft. very high melting points, because a lot of strong In an alloy, there are atoms of different covalent bonds must be sizes. The smaller or bigger atoms distort broken. the layers of atoms in the pure metal. This • Variable conductivity - means that a greater force is required for Diamond does not conduct the layers to slide over each other. The electricity. Graphite contains alloy is harder and stronger than the pure free electrons, so it does metal. conduct electricity. Solid Nano Science Carbon Nanotubes • have a fixed shape and cannot flow, Properties and uses because their particles cannot move • Nanoparticulate materials have many from place to place uses. These include: Nanotubes are a type of fullerene and are molecular- • cannot be compressed (squashed), • medical treatments scale tubes of carbon arranged similarly to the layers because their particles are close • cosmetics, deodorants and in graphite. together and have no space to move sunscreens into • electronics Carbon nanotubes have a very high melting point, as Liquid • catalysts each carbon atom is joined to three other carbon Small sizes • flow and take the shape of their atoms by strong covalent bonds. This also leaves Sunscreens harmful ultraviolet light container, because their particles can each carbon atom with a spare electron, which forms from the sun reaching the skin. oxide move around each other a sea of delocalised electrons within the tube, blocks ultraviolet light, so is used in • cannot be compressed, because their meaning nanotubes can conduct electricity. sunscreens. Bulk zinc oxide is white, but particles are close together and have no nanoparticulate zinc oxide is invisible on space to move into the skin. Many people prefer nanoparticulate sunscreen for this reason. Gas How Ionic Compounds Conduct Electricity Change of State • flow and completely fill their container, A substance can conduct electricity if: because their particles can move quickly Substances can exist as a solid, liquid or • it contains charged particles, such as ions, and in all directions gas. Converting from one state to another • these particles are free to move from place to • can be compressed, because their usually involves heating or cooling. place particles are far apart and have space to • Heat must be supplied to a substance An ionic compound can conduct electricity when: move into for it to melt, evaporate or boil. For • it has melted to form a liquid, or example, you need to heat ice to melt it, • it has dissolved in water to form Polymers and you need to heat water to make an aqueous solution steam. Both these processes allow ions to move from place he simplest definition of a polymer is long • Heat must be removed from a to place. Ionic compounds cannot conduct electricity chain formed by joining many smaller substance to condense or freeze it. In in the solid state because their ions are held in fixed other words, the substance must be molecules, called monomers When positions and cannot move. Forming Positive Ions monomers join with other monomers cooled down. Forming Negative Ions through the process of creating covalent Metal atoms lose electrons from their outer shell bonds, they form larger molecules, called The outer shells of non-metal atoms gain electrons when they form ions: polymers. when they form ions: • the ions are positive, because they have • the ions formed are negative, because they have more protons than electrons more electrons than protons • the ions formed have full outer shells • the ions have the electronic structure of a • the ions have the electronic structure of a noble (group 0 element), with a full outer shell gas (group 0 element), with a full outer shell • For elements in groups 6 and 7, the charge on the • For elements in groups 1, 2 and 3, the number of ion is equal to (8 minus group number). electrons lost is the same as the group number.

Hydrogen Bonding in Water Polymer Strength

Hydrogen-bonding forms in liquid water as Different polymers have different properties, depending on the the hydrogen atoms of one water molecule monomers they are made from and the conditions under which these are attracted towards the oxygen atom of a monomers were joined together. This means that different polymers neighboring water molecule; generally, a have different uses. For example, poly(ethene) can be made in low proton shared by two lone electron pairs. density and high density forms. Low density poly(ethene) has a structure where the polymer chains are branched and this means that the molecules are arranged randomly. High density poly(ethene) has less branching of the polymer chains, so the molecules line up much more closely. Ionic bonding Covalent bonding Draw the dot and cross diagram to show

the covalent bonding in Nl2 C2 Bonding, structure Describe ionic bonding Describe covalent bonding and the properties of matter AQA Trilogy What bonds together? What bonds together?

Define the following terms: Ionic bonding is represented with dot Covalent bonding is represented with Draw the dot and cross diagram to show

Ion and cross diagrams dot and cross diagrams. the covalent bonding in H2O The covalent bond between two Electrostatic force Sodium chloride is shown below: hydrogen atoms is shown below:

Polymer

Allotrope

Write the charge of the following atoms Draw the dot and cross diagram for Draw the dot and cross diagram to show Draw the dot and cross diagram to show when they form ions: magnesium oxide (MgO) the covalent bonding in Cl2 the covalent bonding in CH4 Na Mg Cl K O Br S Ca

Give properties of ionic compounds Draw the dot and cross diagram for Draw the dot and cross diagram to show Draw the dot and cross diagram to show

• magnesium chloride (MgCl2) the covalent bonding in O2 the covalent bonding in HCl

•

• Diamond Metallic bonding Metallic bonding Number of covalent bonds from each Describe metallic bonding C2 Bonding, structure carbon

and the properties of Melting point is low / high / very high matter Why doesn’t it conduct What bonds together? AQA Trilogy electricity?

There are several ways to represent Graphite Why are most metals: Draw a diagram to show why alloys are covalent bonds: Number of covalent bonds from each solid at room temperature? harder than pure metals carbon

Melting point is low / high / very high Good conductors of electricity and heat Why does it conduct electricity?

The repeating unit of poly(ethene) is Write about the uses of Draw a diagram to show why most shown below. What is the molecular Fullerenes like Bucky balls metals are malleable formula of poly(ethene) and nanotubes

Predict the state of: Bromine at room temperature (25oC) at room temperature (25oC) Oxygen at – 220oC

The reason that most polymers are solid Name the process: Draw particle diagrams to show a solid, Ethanol melts at -114oC and boils at at room temperature is: Solid  liquid liquid and a gas 78oC. Predict the state at: Liquid  gas o Gas  liquid -150 C Liquid  solid solid liquid gas 0oC

25oC

100oC