mark me brainliest and follow me2.1 Definitions:Melting point: temperature at which the solid and liquid forms of a pure substance can exist in equilibrium. As heat is applied to a solid, its temperature will increase until the melting point is reached.Boiling point: temperature at which the pressure exerted by the surroundings upon a liquid is equaled by the pressure exerted by the VAPOR of the liquidDistillation: Distillation is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation.Physical change: It is the change in the physical state (either solid liquid or gas of the substance)Chemical change: chemical reaction involving the rearrangement of the ATOMS of one or more substances and a change in their chemical properties or composition, resulting in the formation of at least one new substanceNeutralization: It is the reaction of an equally strong acid with an equally strong base, forming a neutral compound and waterEndothermic reaction: The reaction in which Heat or energy must be supplied in order to proceed the reactionExothermic reaction: The reaction in which heat or energy is liberated after the reaction takes placeCombination reaction: It is the reaction in which two or more reactants combine together to form a productDecomposition reaction: It is the reaction in which one REACTANT decomposes into two or more productsDisplacement reaction: It is the reaction in which an element of higher reactivity DISPLACES another element of lower reactivity2.2 Questions:Physical changes examples: Melting of iceMelting of buttervaporization of watercutting of paperMelting of ice- popsChemical changes examples:Rustingcorrosionburning of paperDigestion foodpreparation of food substancesLook at the attachment for reactivity seriesEvolution of gas:Zn + 2HCl = ZnCl₂ + H₂ (gas)PCl₅ (on heating) = PCl₃ + Cl₂ (gas)Change in color:2KMnO₄ (deep purple) + 5HCOO-COOH + 8HCl = 10CO₂ + MnCl₂ (colorless) + 4H₂OCuSO₄ (anhydrous) (it is colorless) + 5H₂O = CuSO₄.5H₂O (blue color)Formation of precipitate:2KI + PbCl₂ = PbI₂ (ppt) + 2KClNa₂SO₄ + BaCl₂ = 2NaCl + BaSO₄ (ppt)Evolution of energy:2Mg + O₂ = 2MgO (light energy)NaOH + HCl = NaCl + H₂O (heat energy)Absorption of energy: CaCO₃ (heat energy is absorbed) = CaO + O₂2AgCl (light energy is absorbed) = 2Ag + Cl₂2.3 Chemical formulae:1. Ca₃(PO₄)₂2. NaHCO₃3. MgCl₂4. CuSO₄5. NaClO₃6. Mg₃N₂7. Al(OH)₃8. KHSO₃9. ZnS10. FeCl₂2.4 Balancing and naming1. 2Mg + O₂ = 2MgO (Combustion reaction)2. H₂ + Cl₂ = 2HCl (Combination reaction)3. Cu + 2AgNO₃ = Cu(NO₃)₂ + 2Ag (displacement reaction)4. CaCO₃ = CaO + O₂ (decomposition reaction)5. Fe + CuSO₄ = FeSO₄ + Cu (displacement reaction)6. NaOH + HCl = NaCl + H₂O (neutralization reaction)7. 2KI + PbCl₂ = PbI₂ (ppt) + 2KCl (precipitation reaction)8. 2KBr + Cl₂ = 2KCl + Br₂ (Displacement reaction)9. 2KClO₃ = 2KCl + 3O₂ (Decomposition reaction)10. 2Fe + S₈ = 8FeS (Combination reaction)