UPDATED GCSE EDEXCEL TRIPLE SCIENCE CHEMISTRY PAPER 2 2024/2025 QUESTION PAPER ALREADY PASSED

What does 'aq' mean? - answer Aqueous - it is dissolved in water Water - formula - answer H20 Ammonia - formula - answer NH3 Carbon Dioxide - formula - answer CO2 Hydrogen - formula - answer H2 Chlorine - formula - answer Cl2 Oxygen - formula - answer O2 Ammonium (ion) - formula - answer NH4 (+) Hydroxide (ion) - formula - answer OH (-) Nitrate (ion) - formula - answer NO3 (-) Carbonate (ion) - formula - answer CO3 (2-) Sulfate (ion) - formula - answer SO4 (2-) What do you leave out of an ionic equation? - answer Spectator ions - ions that do not change in the reaction What does the 'Oxidising' symbol look like and what does it mean? - answer Provides oxygen which allows materials to burn more fiercely What does the 'Environmental Hazard' symbol look like and what does it mean? - answer Harmful to organisms and the environment What does the 'Toxic' symbol look like and what does it mean? - answer Can cause death e.g. by swallowing, breathing in, absorption through skin What does the 'Harmful' symbol look like and what does it mean? - answer Can cause irritation e.g. blistering of the skin What does the 'Highly Flammable' symbol look like and what does it mean? - answer Catches fire easily What does the 'Corrosive' symbol look like and what does it mean? - answer Destroys materials, including living tissues What is a risk assessment? - answer The process of detecting hazards and assessing associated risks in an experiment What did John Dalton describe atoms as? - answer 'Solid spheres' In 1897, what did J J Thompson suggest? - answer A positively charged 'pudding' with electrons in was what an atom was Who showed that the Plum pudding Model was wrong? - answer Ernest Rutherford What was the gold foil experiment? - answer Rutherford sent a beam of Alpha particles at a thin piece of gold. Some of the particles rebounded. What did the gold foil experiment conclude? - answer Rutherford concluded that most of the atom is empty space The nucleus must be positive as it repels positive particles. He called these protons. Who made the current atom model? - answer Niels Bohr Relative mass of parts of an atom: - answer Proton: 1, Neutron: 1, Electron: 1/2000 Relative charge of parts of an atom: - answer Proton: +1, Neutron: 0, Electron: -1 What does the atomic number tell you? - answer number of protons ( and electrons) What does the mass number tell you? - answer total number of protons and neutrons What are isotopes? - answer Atoms of the same element with different numbers of neutrons Define 'Relative Atomic Mass' : - answer The average mass of an atom compared with 1/12 of the mass of Carbon 12 How can relative atomic mass be written? - answer A(r) Relative atomic mass formula - answer Sum of (isotope abundance x isotope mass number) / sum of abundances of all the isotopes Who made the first proper periodic table? - answer Dmitri Mendeleev How did Mendeleev organise his periodic table? - answer by mass, and columns contained elements with similar properties How did Mendeleev predict not yet found elements? - answer He realised there must be elements with a certain mass to fit the properties of each column. Electron shell numbers - answer 2,8,8 Name for a negative ion - answer Anion Name for a positive ion - answer Cation Which groups are most likely to form ions? - answer Groups 1,2,6,7 Which group is known as the 'nobel gases'? - answer Group 8 What ions will metals be? - answer They will be cations What ions will non-metals be? - answer They will be anions How does ionic bonding work? - answer An electron is stolen, ions form, ions stick together What diagram do you use to show ionic compounds? - answer Dot and cross diagrams What structure do ionic compounds have? - answer Regular lattice structure Why do ions have high melting and boiling points? - answer Strong electrostatic attraction between oppositely charged ions are hard to break ionic compound properties - answer High melting and boiling points, don't conduct electricity, dissolve in water Why don't ions conduct electricity? - answer The ions are fixed in place and can't move What is a covalent bond? - answer Sharing of electrons between atoms Examples of covalent bonds - answer H2, O2, H20, CL2 properties of covalent compounds - answer low melting and boiling points; weak intermolecular attractions What are polymers? - answer long chains of repeating units