Gcse Aqa Chemistry: Paper 1 Exam Questions (188 Terms) With Verified Definitions Updated 2024

Properties and Trends for Halogens/Group 7 (Appearance, Reactivity, Compound properties, Boiling/Melting points, density) {Ans: - Non-metals - Diatomic (exist in covalently bonded pairs to become stable) - They make halide salts (e.g. Chlorine in Sodium Chloride) - All are very reactive as they need only one electron to become stable and the reactivity decreases down the group because the distance between the outer shell and nucleus increases, so the electron is weakly attracted, and so in a displacement reaction (e.g. in a salt), the halogens would switch places when they come together as the electron is then more strongly attracted to the other nucleus so it moves and the halogen displaces the other - Low melting/boiling points, increase down the group as the atoms get heavier}Acid {Ans: Substance that produces H+ ions in aqueous solution}Method of separation for Soluble solid*s* dissolved in solvent {Ans: Chromatography}Fullerene uses {Ans: Delivery of drugs (hollow part) Lubricants in metal as it can roll Catalysts}Metal hydroxide + acid {Ans: Metal hydroxide + acid → metal salt + water}Red litmus paper results {Ans: Acidic solution: Stays red Neutral solution: Stays red Alkaline solution: Turns blue}