13 chapters · 8 questions each · Click any chapter to expand
Balance: Fe + H2O → Fe3O4 + H2.
Identify the type of reaction and balance: AgNO3 + NaCl → AgCl + NaNO3.
Define oxidation and reduction. Give one example of each.
Why is the burning of a candle considered both a physical and a chemical change?
State two methods to prevent rancidity in food.
What happens when an iron nail is dipped in copper sulphate solution? Write the equation.
Why is respiration considered an exothermic reaction?
What is corrosion? List two methods to prevent it.
Why does dry HCl gas not change the colour of dry litmus paper?
What is the pH of a neutral solution? Name an indicator used to test pH.
Write the chemical equation for the reaction of NaOH with HCl.
Why does a bee sting cause pain? Name one common remedy.
What is plaster of Paris? Write its chemical formula and one use.
How is bleaching powder prepared? Give two uses.
Why is baking soda used in cooking? Give the equation when it is heated.
State the importance of pH in our digestive system.
Define the reactivity series of metals. Write the metals in decreasing order of reactivity.
Why is sodium kept under kerosene?
Write the chemical equation for the thermit reaction. State its industrial use.
Why are ionic compounds soluble in water and insoluble in kerosene?
Differentiate between roasting and calcination with one example each.
State two methods to prevent corrosion of iron.
Why is electrolysis used for the extraction of highly reactive metals?
Compare the physical and chemical properties of metals and non-metals (any four points).
Why is carbon tetravalent? Explain with its electronic configuration.
Write the next homologue of: (i) CH3-CH2-OH (ii) CH4.
Define isomerism. Draw the structural isomers of butane.
Differentiate between saturated and unsaturated hydrocarbons with examples.
What happens when ethanol is heated with conc. H2SO4 at 443 K? Write the equation.
Write the equation for esterification and state its industrial use.
Why do soaps not lather well in hard water? Why are detergents better in hard water?
State one chemical test to distinguish between ethanol and ethanoic acid.
Define photosynthesis and write the balanced chemical equation.
Differentiate between aerobic and anaerobic respiration with examples.
Draw a labelled diagram of the human alimentary canal.
Why is the human heart called a double circulation pump?
Describe the structure and function of a nephron.
How does transportation of water occur in plants? Explain the role of root pressure and transpiration.
State the role of saliva in digestion.
Why do herbivores have a longer small intestine than carnivores?
Draw the structure of a neuron and label its parts.
What is a reflex action? Explain with the help of a reflex arc.
Differentiate between the central and peripheral nervous systems.
Name the hormone secreted by the pancreas and state its function.
What will happen if the secretion of thyroxine becomes too low?
Define tropism. Name and explain any two types with examples.
State the functions of auxin and abscisic acid.
How is the brain protected in the human body?
List four modes of asexual reproduction with one example each.
Draw a labelled diagram of a flower and label its essential parts.
Differentiate between self-pollination and cross-pollination.
Describe the structure of the male reproductive system in humans.
What is the role of the placenta in pregnancy?
Name two sexually transmitted diseases caused by viruses.
Why is variation important in sexual reproduction?
What are different methods of contraception? Give one example of each.
State Mendel's laws of inheritance.
Show a monohybrid cross with tall (T) and short (t) plants. Give the F2 genotypic and phenotypic ratios.
Show a dihybrid cross between RrYy × RrYy and give the phenotypic ratio.
Define genotype and phenotype with examples.
How is sex determined in humans? Draw a flow chart.
Why are variations important for the survival of a species?
Differentiate between dominant and recessive characters.
A pure red flower plant (RR) was crossed with a pure white flower plant (rr). Find the genotype and phenotype of F1 and F2 generation.
State the laws of reflection of light.
An object is placed 20 cm in front of a concave mirror of focal length 15 cm. Find the position and nature of the image.
State Snell's law and define refractive index.
A convex lens of focal length 10 cm forms an image of an object 15 cm away. Find the position and magnification.
Define power of a lens. Find the power of a lens with focal length 25 cm.
Draw the ray diagram for an object placed beyond C in front of a concave mirror.
Differentiate between real and virtual images.
Why does a stick appear bent when partly immersed in water?
Draw a labelled diagram of the human eye and state the function of each part.
Define myopia. With a ray diagram, show how it is corrected.
A person can read at 25 cm but cannot read clearly beyond 1 m. Find the power of the corrective lens.
What is meant by dispersion of light? Draw a diagram showing dispersion through a prism.
Why does the sky appear blue?
Why does the sun appear reddish at sunrise and sunset?
Explain the cause of the twinkling of stars.
Distinguish between myopia and hypermetropia.
State Ohm's law and derive V = IR.
A wire of resistance 20 Ω is bent in a closed circle. Find the resistance across two diametrically opposite points.
Three resistors of 4 Ω, 6 Ω and 12 Ω are connected in parallel. Find the equivalent resistance.
A bulb is rated 100 W, 220 V. Find the resistance and the current through it.
Calculate the electrical energy in kWh when a 60 W bulb is used for 5 hours daily for 30 days.
State two factors on which the resistance of a conductor depends. Define resistivity.
Draw a circuit diagram for series and parallel combination of three resistors.
State Joule's law of heating. List two applications based on this principle.
State the right-hand thumb rule. Find the direction of magnetic field around a straight current-carrying wire.
Describe with a diagram the construction and working of an electric motor.
State Fleming's left-hand and right-hand rules. Where is each used?
What is electromagnetic induction? State Faraday's law.
Differentiate between AC and DC.
Why is the earth wire used in electric appliances?
Describe the construction and working of an AC generator with a diagram.
State the function of a fuse in a domestic circuit.
Define ecosystem. Give two examples of natural ecosystems.
Construct a food chain in a grassland ecosystem.
State the 10 percent law of energy flow in an ecosystem.
What is biological magnification? Give one example.
Why is the ozone layer important? Name the gases responsible for its depletion.
Differentiate between biodegradable and non-biodegradable substances with examples.
List four ways in which we can manage waste in our homes.
Why are decomposers important in an ecosystem?
