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polarization, property of certain electromagnetic radiations(such as radio waves, visible light, and gamma rays) in which the direction and magnitude of the vibrating electric field are related in a specified way

Where 3mols of H2So4 = 1 mol of (Al2SO4)3 y mols of H2SO4 = 0.5 mol of (Al2SO4)3 Then cross multiply to have: y = \(\frac{3\times0.5}{1}\) y = 1.5 moles

The ionisation energy is the minimum energy required to remove the most loosely bound electron of an isolated gaseous atom, positive ion, or molecule. Fluorine has the highest ionization energy when assessed through the trend on the periodic table.

Properties of a good standard solution High purity. Stability (low reactivity) Low hygroscopicity (to minimize weight changes due to humidity) High equivalent weight (to minimize weighing errors) Non-toxicity. Ready and cheap availability. High molecular mass

Cation which is lower in the series (less electropositive) will show a greater tendency to be discharged.

½Ke\(^{2}\) = ½mv\(^{6}\) ½ x 200 x (0.05)\(^{2}\) = ½ x 0.02 x v\(^{2}\) v\(^{2}\) = 25 v = 5 m s\(^{-1}\)

The expected answer is (a) Identification of labelled physical quantities P - initial velocity/ velocity of projection b - angle of projection H - maximum height reached R - range/horizontal distance (covered) (b) Equation showing relationship between P, g and Rmax Rmax = \(\frac{p^2}{g}\)

Observable phenomena in which waves behave like a particle - reflection; - refraction; - diffraction; - polarization; - interference; - Compton effect; - blackbody radiation

Magnetic elements that determine the earth’s magnetic field at a point - Angle of dip/inclination - angle of declination/variation - horizontal component of the earth’s magnetic field

Explanation of terms (a) Free electrons; Negative charge carriers (b) Holes; Positive charge carriers

(a) Principle of operation of fibre optics - Total internal reflection of light (b) Applications of fibre optics in medicine As: - light guides - imaging tools - laser for surgery

(a) Definition of diffusion; The process by which molecules of different substances move randomly among one another. OR Intimate mixing of molecules/atoms/particles of different substance (as a result of kinetic energy) (b) Factors that affect the rate of diffusion - density of substance - mass of substance - temperature

(a) (i) Newton’s law of Universal Gravitation; Any two bodies in the universe attract each other with a force that is (directly) proportional to the product of their masses and inversely proportional to the square of the distance between them. (ii) Definition of gravitational field; A region/space in which gravitational force is felt / experienced. (b) (i) Derivation of the equation relating G and g at the surface of the earth F = \(\frac{GMm}{R^2}\) mg = \(\frac{GMm}{R^2}\) g = \(\frac{GM}{R^2}\) (ii) Assumptions for which equation holds; - mass of the earth is concentrated at its centre - earth is spherical - earth is not rotating - possesses uniform density. (c) Calculation of the force of attraction between a star and the earth; F = \(\frac{GM_sM_e}{r_2}\) = 6.67 x 10\(^{11}\) [\(\frac {(2 \times 10^{30}) (5.98 \times 10^{24})} {(1.5 \times 10^{11})^2}\)] = 3.55 x 10\(^{22}\)N (d) (i) Definition of escape velocity; The minimum uni-directional speed/velocity required by a body to leave the gravitational field/influence of a planet (ii) Differences between acceleration of free fall (g) and universal gravitational constant (G) g G Its unit is N m2 kg-2 Its unit is m s-2 / N kg-1 It is constant everywhere It varies from place to place It is a scalar quantity It is a vector quantity

(a)(i) Explanation of latent heat When a substance is changing state, it absorbs/gives out thermal/heat energy which does not result in temperature change. This heat absorbed or given out during change of state is known as latent heat. (ii) Factors that affect the rate of evaporation of a liquid - exposed surface area of the liquid - temperature of the liquid - wind / draught - humidity / amount of water vapour - nature of the liquid - air pressure. (b) Explanation of observations (i) Water in a clay pot is cooler than water in a closed plastic container The clay pot has pores which allow evaporation to take place. In the process of evaporation, molecules take latent heat from the bulk of the water, leaving the water cooler; but the plastic container does not have pores (to allow for evaporation). (ii) Food gets cooked faster in a pressure cooker than in an ordinary cooking pot With the pressure cooker, increased pressure raises the boiling point of water within a short period. This leads to faster cooking. Ordinary cooking pot operates at normal atmospheric pressure. (c) Effects of heat on a substance Change of/in: - state - temperature - dimension - colour - electrical resistance (d) (i) Determination of latent heat of fusion of the body Heat supplied by electric heater in the first 1400 s IVt\(_1\) = mlf mlf = 12 x 40 x 1400 = 6.72 x 105J (ii) Determination of Specific heat capacity of the body IVt\(_2\) = mc\(\Delta \theta\) c = \(\frac{IVt_2}{m \Delta \theta}\) = \(\frac{12 \times 40 \times 72}{1.5 \times 60}\) = 384 Jk\(^{-1}\) K\(^{-1}\)

(a) (i) Definition of force Action/push/pull that changes/tends to change the state of rest or of uniform motion in straight line. Its unit is newton (N) (ii) Types of solid friction - dynamic (friction) - static (friction) (b) (i) Velocity-time graph for journey