Grade 11 Physical Sciences 2024 Past Paper - PDF

GRADE 11 PHYSICAL SCIENCES 2024 DEFINITIONS [2015 EXAMINATION GUIDELINES] PART A: PHYSICS (P1) NEWTON’S LAWS 1.1 Normal force: is the force or the component of a force which a surface exerts on an object with which it in contact and which is perpendicular to the surface. 1.2 Frictional force: is...

GRADE 11 PHYSICAL SCIENCES 2024 DEFINITIONS [2015 EXAMINATION GUIDELINES] PART A: PHYSICS (P1) NEWTON’S LAWS 1.1 Normal force: is the force or the component of a force which a surface exerts on an object with which it in contact and which is perpendicular to the surface. 1.2 Frictional force: is the force which opposes the motion of an object and which acts parallel to the surface. 1.3 Static frictional force: is the force that opposes the tendency of motion of a stationary object relative to a surface. 1.4 Kinetic frictional force: is the force that opposes the motion of a moving object relative to the surface. 1.5 Newton’s first law: a body will remain in its state of rest or motion at a constant velocity unless a non-zero resultant / net force acts on it. 1.6 Inertia: Is the resistance of an object to any change in its state of motion. 1.7 Newton's second law of motion: When a net/resultant force acts on an object, the object will accelerate in the direction of the force and the acceleration is directly proportional to the force and inversely proportional to the mass of the object. 1.8 Newton's third law of motion: When object A exerts a force on object B, object B SIMULTANEOUSLY exerts an oppositely directed force of equal magnitude on object A. 1.9 Newton's Law of Universal Gravitation: Each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. 1.10 Weight: is the gravitational force the Earth exerts on any object on or near its surface. 1.11 WEIGHTLESSNESS: Is the sensation experienced when all contact forces are removed, 1.12 Mass: Is the amount of matter in a body. 1 2: VECTORS 2.1 Vector quantity: A quantity that has both magnitude and direction. 2.2 Scalar quantity: A quantity that has only magnitude but no direction. 2.3 Resultant: A single vector having the same effect as two or more vectors together. 3: ELECTROSTATICS 3.1 Coulomb's law: The magnitude of the electrostatic force exerted by one point charge on another point charge is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them. 3.2 An electric field: is a region of space in which an electric charge experiences a force. 3.3 Electric field strength at a point: The electric field at a point is the electrostatic force experienced per unit positive charge placed at that point. 4: ELECTRIC CIRCUITS 4.1 Ohm's law in words: The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature. 4.2 Ohmic conductor: conductor which obeys Ohm’s Law 4.3 No-Ohmic conductor: conductor which obeys Ohm’s Law 4.4 Power: The rate at which work is done or energy is transferred. 4.5 kilowatt-hour (kWh): Is the use of 1 kilowatt of electricity for 1 hour. 5: ELECTROMAGNETISM 5.1 Faraday’s Law of electromagnetic induction: The magnitude of induced EMF is directly proportional to the rate of change in the magnetic flux linkage with the conductor 2  PART B: CHEMISTRY (PAPER 2) 1 ATOMIC COMBINATIONS: MOLECULAR STRUCTURE 1.1 A chemical bond: a mutual attraction between two atoms resulting from the simultaneous attraction between their nuclei and the outer electrons. (NOTE: The energy of the combined atoms is lower than that of the individual atoms resulting in higher stability.) 1.2 Valence electrons or outer electrons: The electrons in the highest energy level of an atom in which there are electrons. 1.3 A covalent bond: The sharing of electrons between two atoms to form a molecule. 1.4 A dative covalent bond(or coordinate covalent bond): the type of covalent bond where the shared pair of electrons between an atom and ion is contributed by only the atom. 1.5 Molecule: A group of two or more atoms covalently bonded and that function as a unit. 1.6 A bonding pair: A pair of electrons that is shared between two atoms in a covalent bond. 1.7 A lone pair: A pair of electrons in the valence shell of an atom that is not shared with another atom. 1.8 Electronegativity: A measure of the tendency of an atom in a molecule to attract bonding electrons. 1.9 A non-polar covalent bond: A bond in which the electron density is shared equally between the two atoms. An example is the bond between two H atoms. 1.10 A polar covalent bond: A bond in which the electron density is shared unequally between the two atoms. An example is the bond between an H atom and a Cℓ atom 1.11 Bond energy: The energy needed to break one mole of its molecules into separate atoms. 1.12 Bond length: The average distance between the nuclei of two bonded atoms. 2 INTERMOLECULAR FORCES (VAN DER WAALS FORCES) 2.1 Intermolecular forces: Forces between molecules. 2.2 Interatomic forces (intramolecular forces): Forces between atoms in a molecule. 2.3 Boiling point: The temperature at which the vapour pressure of a substance equals atmospheric pressure. 2.4 Melting point: The temperature at which the solid and liquid phases of a substance are at equilibrium. 2.5 Vapour pressure: The pressure exerted by a vapour at equilibrium with its liquid in a closed system. 3 2.6 Solubility: The property of a solid, liquid, or gaseous chemical substance (solute) to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution. 3 IDEAL GASES AND THERMAL PROPERTIES 3.1 An ideal gas: Is a gas:  That has identical particles of zero volume  With no intermolecular forces between particles  In which all collisions of the molecules with themselves or the walls of the container, are perfectly elastic. NOTE: a) The conditions under which real gases deviate from ideal gas behaviour are at high pressures and low temperatures. b) the conditions under which a real gas approaches ideal gas behaviour (behave like ideal gas) are low pressures and high temperatures. 3.2 Boyle's law: The pressure of an enclosed gas is inversely proportional to the volume it occupies at constant temperature. 4 QUANTITATIVE ASPECTS OF CHEMICAL CHANGE 4.1 One mole: The amount of substance having the same number of particles as there are atoms in 12 g carbon-12. 4.2 Molar mass: The mass of one mole of a substance 4.3 Avogadro's Law: One mole of any gas occupies the same volume at the same temperature and pressure. 4.4 Concentration: The amount of solute per litre of solution. 4.5 Limiting reagent: A reagent that is completely used up in a chemical reaction. 5 ENERGY AND CHEMICAL CHANGE 5.1 Heat of reaction (ΔH): The energy absorbed or released per mole in a chemical reaction. 5.2 Exothermic reaction: A reaction that releases energy. 5.3 Endothermic reaction: A reaction that absorbs energy 5.5 Activation energy: The minimum energy needed for a reaction to take place. 5.6 Activated complex: The unstable transition state from reactants to products. 4 6 TYPES OF REACTIONS 6.1 Acid-base reactions 6.1.1 According to Arrhenius theory According to Lowry-Brønsted theory An acid: is a substance that An acid: is a proton/H+ ion donor. produces hydrogen ions (H+)/hydronium ions (H3O+) when it dissolves in water. A base: is a substance that produces Base: is a proton/H+ ion acceptor. hydroxide ions (OH-) when it dissolves in water. 6.1.2 Conjugate acid-base pair: Is acid-base pair which differ by one proton(H+). 6.1.3 Ampholyte (amphiprotic substance): A substance that can act as either acid or a base. 6.1.4 An acid-base indicator: Is a weak acid, or a weak base, which colour changes as the H+ ion concentration or the OH- ion concentration in a solution changes. 6.1.5 Neutralisation reaction: Is a reaction between an acid and a base to form salt and water. 6.2 Redox reactions 6.2.1 Oxidation number: is a number assigned to an element to keep track of the movement of electrons during a reaction. 6.2.2 Redox (oxidation-reduction) reaction: Is a reaction involving an electron transfer. OR: A reaction involving changes in oxidation numbers. 6.2.3 Oxidation Reduction Is the loss of electrons Is the gain of electrons (Zn → Zn2+ + 2e-) (Cu2+ +2e- → Cu ) Is the increase in oxidation number Is the decrease in oxidation number. (Zn → Zn2+ + 2e- from 0 to 2+) (Cu2+ +2e- → Cu from 2+ to 0) 6.2.4 Reducing agent Oxidising agent A substance that is oxidised (ie Zn) A substance that is reduced (ie Cu2+) (Zn → Zn2+ + 2e-) (Cu2+ +2e- → Cu ) A substance that loses electrons A substance that gains electrons (ie Zn) (Zn → Zn2+ + 2e-) (ie Cu2+) (Cu2+ +2e- → Cu ) A substance whose oxidation A substance whose oxidation number number increases (ie Zn) decreases (ie ) Cu2+) (Zn → Zn2+ + 2e-) (Cu2+ +2e- → Cu) 5