Class 10 Science
17 Practice Questions — The answers are hidden. Reveal them to check your answers. The Timed Test will be available in Phase 3.
A decomposition reaction splits one compound into two or more products. Example: heating limestone CaCO₃ → CaO + CO₂, or electrolysis of water.
Look for heat, light or electricity as the energy that breaks the reactant.
A redox reaction has oxidation and reduction together. Copper is oxidised (gains oxygen); oxygen is reduced.
If a metal gains oxygen, that metal is oxidised.
Law of conservation of mass: mass (and number of each atom) on the reactant side equals the product side.
Never change formulae — only change coefficients.
If mouth pH falls below about 5.5, enamel (calcium phosphate) starts dissolving. Bacteria produce acid from sugar, so rinsing and cleaning keeps pH safer.
Link sugar → acid → low pH → enamel damage.
These practice sets use original GKSchools wording — they are not a verbatim dump of the NCERT textbook. “Important” means high-weight practice for the chapter, not a claim that these are previous-year exam questions.
Follow this loop every day: mixed test, current affairs, then today's subject. A new set arrives tomorrow.
After this page, use these three links — do not open a random page.
More sets from the same cluster — stay on this topic.
Timed papers with a scorecard — start any time, then return to a related quiz above.
