STUDY AREA 1 – The Periodic Table This area of study investigates the structure and behaviour of atoms, they way they are arranged in and trends across the periodic table and introduces the concept of calculations involving atoms. This area of study investigates the structure and behaviour of atoms, they way they are arranged in and trends across the periodic table and introduces the concept of calculations involving atoms.

THE KINETIC THEORY OF MATTER This theory explains the behaviour of atoms whether they are in a solid, liquid or gaseous state. But what is the theory?

Kinetic theory states that: All matter is made up of tiny, invisible moving particles All matter is made up of tiny, invisible moving particles Particles of different substances have different sizes Particles of different substances have different sizes Lighter particles move faster than heavier ones at a given temperature Lighter particles move faster than heavier ones at a given temperature As the temperature increases, the particles move faster As the temperature increases, the particles move faster In a solid state, the particles are close together and vibrate in fixed positions In a solid state, the particles are close together and vibrate in fixed positions In a liquid state, the particles are further apart, have more energy and can move around each other In a liquid state, the particles are further apart, have more energy and can move around each other In a gaseous state, the particles are far apart, move rapidly and randomly with greater energy and take up available space around them In a gaseous state, the particles are far apart, move rapidly and randomly with greater energy and take up available space around them

Atomic theory timeline 400BC: Democritus 1808: John Dalton 1897: Sir J.J Thompson 1911: Ernest Rutherford 1913: Niels Bohr 1932: Sir James Chadwick 2007: ?

Atomic structure What are atoms made of? What are atoms made of? Where do we find information about each atom or element? Where do we find information about each atom or element? What do the numbers and symbols mean? What do the numbers and symbols mean? How are the elements arranged on the periodic table? How are the elements arranged on the periodic table?

The periodic table Who developed the periodic table? Who developed the periodic table? What patterns exist? What patterns exist?

Electron configuration Electrons are found in energy shells that surround the nucleus (like layers around an onion) Electrons are found in energy shells that surround the nucleus (like layers around an onion) The shells are numbered 1 – 7 HOWEVER, within each shell there are sub-shells which fill up in a specific order and are lettered s, p, d & f. The shells are numbered 1 – 7 HOWEVER, within each shell there are sub-shells which fill up in a specific order and are lettered s, p, d & f. To make matters more complicated, each sub shell consists of smaller orbitals, each of which can only hold 2 electrons. To make matters more complicated, each sub shell consists of smaller orbitals, each of which can only hold 2 electrons.

Electron configuration Each shell can hold a total of 2n 2 electrons (n = shell No.) Each shell can hold a total of 2n 2 electrons (n = shell No.) What is the order for filling each of the sub shells? What is the order for filling each of the sub shells? □ 1s □ 1s □ 2s □ 2s □□□ 2p □□□ 2p □ 3s □ 3s □□□3p □□□3p □ 4s □ 4s □□□□□3d □□□□□3d □□□4p □□□4p □ 5s □ 5s

Electron configuration Eg. Sodium (Na). Z=11 Therefore there are 11 electrons to place in energy shells. How. Eg. Sodium (Na). Z=11 Therefore there are 11 electrons to place in energy shells. How. Na is in period 3, therefore must occupy 3 shells. Na is in period 3, therefore must occupy 3 shells. Shell 1 = 2e, shell 2 = 8e and shell 3 = 1e Shell 1 = 2e, shell 2 = 8e and shell 3 = 1e (group 1) Written as 1s², 2s², 2p6, 3s1 Written as 1s², 2s², 2p6, 3s1

Trends in the periodic table As you move across a period, the atomic number increases and more electrons are being added to the outer shell. As you move across a period, the atomic number increases and more electrons are being added to the outer shell. What trends does this produce? What trends does this produce? What about as you move down each group. What trends are observed? What about as you move down each group. What trends are observed?

Isotopes Why is the mass number for each element on the periodic table not an even number like the atomic number is? Why is the mass number for each element on the periodic table not an even number like the atomic number is? Because for each atom, there are often more than 1 isotope. An isotope is an element with the same number of protons, but different numbers of neutrons Because for each atom, there are often more than 1 isotope. An isotope is an element with the same number of protons, but different numbers of neutrons Eg. O 16 O 17 O 18 Eg. O 16 O 17 O 18

Quantities in chemistry Atoms are very, very, very etc. small. So how do we calculate how much of a substance to use in a reaction if we can’t count out a certain number of atoms to be used. Atoms are very, very, very etc. small. So how do we calculate how much of a substance to use in a reaction if we can’t count out a certain number of atoms to be used. We use the ‘mass’ instead and something called ‘a mole’ We use the ‘mass’ instead and something called ‘a mole’

Quantities in chemistry When substances react, they do so in exact and reproducible amounts. When substances react, they do so in exact and reproducible amounts. Consider this reaction C(s) + O 2 (g)  CO 2 (g) Consider this reaction C(s) + O 2 (g)  CO 2 (g) One atom of carbon (C) is reacting with one molecule of oxygen (O 2 ) to produce one molecule of carbon dioxide (CO 2 ). One atom of carbon (C) is reacting with one molecule of oxygen (O 2 ) to produce one molecule of carbon dioxide (CO 2 ). If we knew the mass of the atoms and molecules involved, we could predict the quantities of reactants and products. If we knew the mass of the atoms and molecules involved, we could predict the quantities of reactants and products.

The ‘Mole’ The mole is one of the most important concepts in chemistry. The mole is one of the most important concepts in chemistry. The mole is an amount of substance containing a specified number of particles. This “specified” number is called Avogadro's Number and is equal to 6.02 x The mole is an amount of substance containing a specified number of particles. This “specified” number is called Avogadro's Number and is equal to 6.02 x A mole of pure substance:-contains 6.02 x elementary particles (atoms, molecules, ions) and has a mass (in grams) equal to its relative atomic (Ar) or molar mass (M) A mole of pure substance:-contains 6.02 x elementary particles (atoms, molecules, ions) and has a mass (in grams) equal to its relative atomic (Ar) or molar mass (M)

The ‘Mole’ Calculations involving moles. Calculations involving moles. The amount of substance (in mole) can be calculated from the mass of a pure substance using the formula: n = m/M The amount of substance (in mole) can be calculated from the mass of a pure substance using the formula: n = m/M Where: n is the number of moles m is the mass in grams M is the molar mass in g Mol -1 Where: n is the number of moles m is the mass in grams M is the molar mass in g Mol -1

STUDY AREA 2 - MATERIALS This study area examines the different types of bonding that can occur between substances and how this bonding can effect the chemistry of the substance. This study area examines the different types of bonding that can occur between substances and how this bonding can effect the chemistry of the substance.

Bonding Strong types of bonding that form molecules include: Strong types of bonding that form molecules include: ionic, covalent and metallic Weaker forms of bonding between molecules include: Weaker forms of bonding between molecules include: polar, hydrogen and dispersion forces

Metallic bonding About 80% of the known elements are metals About 80% of the known elements are metals Properties of Metals: Properties of Metals: Good conductors of electricity Good conductors of heat Shiny (lustrous) when cleaned MalleableDuctile Generally high density (all solids except mercury) Generally high melting point Why?

Metallic bonding model Metal atoms form positive charged cations by losing their outer shell electrons. These electrons hang around to become delocalised electrons. Delocalised electrons can flow throughout a metal structure but are always surrounding the positive cations to keep them balanced.

MODIFYING METALS TO MAKE THEM MORE USEFUL Few metals are used in their pure form. Most metals have been modified to improve their performance in a particular use. Few metals are used in their pure form. Most metals have been modified to improve their performance in a particular use. Metals can be modified by: Metals can be modified by: alloying them changing their crystal structure

IONIC BONDING Ionic compounds (or salts) are usually products of the combination of metals and non-metals. Ionic compounds (or salts) are usually products of the combination of metals and non-metals. Properties of Ionic Compounds: Properties of Ionic Compounds: High melting temperatures (all solids at room temperature) Hard, but brittle Do not conduct electricity in the solid state Do conduct electricity when molten (or dissolved)

THE IONIC BONDING MODEL Na + Cl → NaCl The Na + and Cl - ‘ions’ arrange themselves into a 3D crystal lattice structure (like metals)

FORMULAE AND NAMING OF IONIC COMPOUNDS What is the formula for sodium chloride? What is the formula for sodium chloride? What is the name of MgO? What is the name of MgO? What are the rules for finding the formula or name of ionic substances? What are the rules for finding the formula or name of ionic substances?

COVALENT BONDING Occurs between NON METALS only Occurs between NON METALS only Although non metals account for only about 20% of the 100 or so elements, they combine to form over 90% of the compounds we’ve named to date. Although non metals account for only about 20% of the 100 or so elements, they combine to form over 90% of the compounds we’ve named to date. There are 2 types of non metal substances: There are 2 types of non metal substances: Molecular substances Covalent lattice substances

MOLECULAR SUBSTANCES Properties of Molecular Substances Properties of Molecular Substances Low melting and boiling points (gases or liquids at room temperature) Non conductors of electricity Generally poor solubility in water

Covalent bonding model Two fluorine atoms can bond by sharing their ‘unpared’ outershell electron Can atoms share more than ONE electron?

Ionic V’s Covalent Bonding

Representing covalent bonds Covalent molecules can be drawn as either electron dot diagrams or structural diagram Covalent molecules can be drawn as either electron dot diagrams or structural diagram H + H → H:H H + H → H - H H H C H H