CBSE Class 9 atomicfoundations — practice questions
25 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 9 atomicfoundations in the app →In the reaction H₂ + O₂ → H₂O, when the products are weighed, the mass equals:The Law of Constant Proportions states that:When an atom LOSES one or more electrons, it becomes:In Lavoisier's experiments, why was it crucial to perform reactions in SEALED containers?Why do water samples from different sources (river, rain, lab) all have the same hydrogen-to-oxygen mass ratioWho proposed the Law of Conservation of Mass?The total mass after a chemical reaction is:The Law of Conservation of Mass was proposed in:Pure water always contains hydrogen and oxygen in the mass ratio:The Law of Constant Proportions is also called the law of:Who proposed the atomic theory?According to Dalton, atoms are:A hydrogen molecule consists of how many atoms?A hydrogen chloride molecule is formed from:Two oxygen atoms in a molecule are joined by a:Hydrogen and chlorine in HCl are joined by a:A compound formed by sharing electrons is called:The water molecule is represented as:CO2 is named:Which prefix indicates four atoms?CO is named carbon:If 12 g of carbon combines with 32 g of oxygen, the carbon dioxide formed is:Sodium chloride has sodium and chlorine in the mass ratio:An atom with fewer than four valence electrons will usually:Decomposing 9 g of pure water gives how much hydrogen?